Ancient Greek religion encompasses the collection of beliefs, rituals, and mythology originating in ancient Greece in the form of both popular public religion and cult practices. These groups varied enough for it to be possible to speak of Greek religions or "cults" in the plural, though most of them shared similarities.
Most ancient Greeks recognized the twelve major Olympian gods and goddesses--Zeus, Hera, Poseidon, Demeter, Athena, Ares, Aphrodite, Apollo, Artemis, Hephaestus, Hermes, and either Hestia or Dionysus--although philosophies such as Stoicism and some forms of Platonism used language that seems to assume a single transcendent deity. The worship of these deities, and several others, was found across the Greek world, though they often have different epithets that distinguished aspects of the deity, and often reflect the absorption of other local deities into the pan-Hellenic scheme.
The religious practices of the Greeks extended beyond mainland Greece, to the islands and coasts of Ionia in Asia Minor, to Magna Graecia (Sicily and southern Italy), and to scattered Greek colonies in the Western Mediterranean, such as Massalia (Marseille). Early Italian religions such as the Etruscan were influenced by Greek religion in forming much of the ancient Roman religion.
While there were few concepts universal to all the Greek peoples, some common beliefs were shared by many.
Ancient Greek theology was polytheistic, based on the assumption that there were many gods and goddesses, as well as a range of lesser supernatural beings of various types. There was a hierarchy of deities, with Zeus, the king of the gods, having a level of control over all the others, although he was not almighty. Some deities had dominion over certain aspects of nature. For instance, Zeus was the sky-god, sending thunder and lightning, Poseidon ruled over the sea and earthquakes, Hades projected his remarkable power throughout the realms of death and the Underworld, and Helios controlled the sun. Other deities ruled over abstract concepts; for instance Aphrodite controlled love. All significant deities were visualized as "human" in form, although often able to transform themselves into animals or natural phenomena.
While being immortal, the gods were certainly not all-good or even all-powerful. They had to obey fate, known to Greek mythology as the Moirai, which overrode any of their divine powers or wills. For instance, in mythology, it was Odysseus' fate to return home to Ithaca after the Trojan War, and the gods could only lengthen his journey and make it harder for him, but they could not stop him.
The gods acted like humans and had human vices. They would interact with humans, sometimes even spawning children with them. At times certain gods would be opposed to others, and they would try to outdo each other. In the Iliad, Aphrodite, Ares and Apollo support the Trojan side in the Trojan War, while Hera, Athena and Poseidon support the Greeks (see theomachy).
Some gods were specifically associated with a certain city. Athena was associated with the city of Athens, Apollo with Delphi and Delos, Zeus with Olympia and Aphrodite with Corinth. But other gods were also worshipped in these cities. Other deities were associated with nations outside of Greece; Poseidon was associated with Ethiopia and Troy, and Ares with Thrace.
Identity of names was not a guarantee of a similar cultus; the Greeks themselves were well aware that the Artemis worshipped at Sparta, the virgin huntress, was a very different deity from the Artemis who was a many-breasted fertility goddess at Ephesus. Though the worship of the major deities spread from one locality to another, and though most larger cities boasted temples to several major gods, the identification of different gods with different places remained strong to the end.
Our ancient sources for Greek religion tell us a good deal about cult but very little about creed, in no small measure because the Greeks in general considered what one believed to be much less importance than what one did. 
The Greeks believed in an underworld where the spirits of the dead went after death. One of the most widespread areas of this underworld was ruled over by Hades, a brother of Zeus, and was known as Hades (originally called 'the place of Hades'). Other well known realms are Tartarus, a place of torment for the damned, and Elysium, a place of pleasures for the virtuous. In the early Mycenean religion all the dead went to Hades, but the rise of mystery cults in the Archaic age led to the development of places such as Tartarus and Elysium.
A few Greeks, like Achilles, Alcmene, Amphiaraus Ganymede, Ino, Melicertes, Menelaus, Peleus, and a great number of those who fought in the Trojan and Theban wars, were considered to have been physically immortalized and brought to live forever in either Elysium, the Islands of the Blessed, heaven, the ocean, or beneath the ground. Such beliefs are found in the most ancient of Greek sources, such as Homer and Hesiod. This belief remained strong even into the Christian era. For most people at the moment of death there was, however, no hope of anything but continued existence as a disembodied soul.
Some Greeks, such as the philosophers Pythagoras and Plato, also embraced the idea of reincarnation, though this was only accepted by a few. Epicurus taught that the soul was simply atoms which dissolved at death, so there was no existence after death.
Greek religion had an extensive mythology. It consisted largely of stories of the gods and how they interacted with humans. Myths often revolved around heroes and their actions, such as Heracles and his twelve labors, Odysseus and his voyage home, Jason and the quest for the Golden Fleece and Theseus and the Minotaur.
Many species existed in Greek mythology. Chief among these were the gods and humans, though the Titans (who predated the Olympian gods) also frequently appeared in Greek myths. Lesser species included the half-man-half-horse centaurs, the nature based nymphs (tree nymphs were dryads, sea nymphs were Nereids) and the half man, half goat satyrs. Some creatures in Greek mythology were monstrous, such as the one-eyed giant Cyclopes, the sea beast Scylla, whirlpool Charybdis, Gorgons, and the half-man, half-bull Minotaur.
There was not a set Greek cosmogony, or creation myth. Different religious groups believed that the world had been created in different ways. One Greek creation myth was told in Hesiod's Theogony. It stated that at first there was only a primordial deity called Chaos, who gave birth to various other primordial gods, such as Gaia, Tartarus and Eros, who then gave birth to more gods, the Titans, who then gave birth to the first Olympians.
The mythology largely survived and was added to in order to form the later Roman mythology. The Greeks and Romans had been literate societies, and much mythology, although initially shared orally, was written down in the forms of epic poetry (such as the Iliad, the Odyssey and the Argonautica) and plays (such as Euripides' The Bacchae and Aristophanes' The Frogs). The mythology became popular in Christian post-Renaissance Europe, where it was often used as a basis for the works of artists like Botticelli, Michelangelo and Rubens.
One of the most important moral concepts to the Greeks was the fear of committing hubris. Hubris constituted many things, from rape to desecration of a corpse, and was a crime in the city-state of Athens. Although pride and vanity were not considered sins themselves, the Greeks emphasized moderation. Pride only became hubris when it went to extremes, like any other vice. The same was thought of eating and drinking. Anything done to excess was not considered proper. Ancient Greeks placed, for example, importance on athletics and intellect equally. In fact many of their competitions included both. Pride was not evil until it became all-consuming or hurtful to others.
The Greeks had no religious texts they regarded as "revealed" scriptures of sacred origin, but very old texts including Homer's Iliad and Odyssey, and the Homeric hymns (regarded as later productions today), Hesiod's Theogony and Works and Days, and Pindar's Odes were regarded as having authority and perhaps being inspired; they usually begin with an invocation to the Muses for inspiration. Plato even wanted to exclude the myths from his ideal state described in the Republic because of their low moral tone.
While some traditions, such as Mystery cults, did uphold certain texts as canonic within their own cult praxis, such texts were respected but not necessarily accepted as canonic outside their circle. In this field, of particular importance are certain texts referring to Orphic cults: multiple copies, ranging from 450 BC to 250 AD, have been found in various locations of the Greek world. Even the words of the oracles never turned into a sacred text. Other texts were specially composed for religious events, and some have survived within the lyric tradition; although they had a cult function, they were bound to performance and never developed into a common, standard prayer form comparable to the Christian Pater Noster. An exception to this rule were the already named Orphic and Mystery rituals, which, in this, set themselves aside from the rest of the Greek religious system. Finally, some texts called hieroi logoi (Greek: ) (sacred texts) by the ancient sources, originated from outside the Greek world, or were supposedly adopted in remote times, representing yet more different traditions within the Greek belief system.
The lack of a unified priestly class meant that a unified, canonic form of the religious texts or practices never existed; just as there was no unified, common sacred text for the Greek belief system, there was no standardization of practices. Instead, religious practices were organized on local levels, with priests normally being magistrates for the city or village, or gaining authority from one of the many sanctuaries. Some priestly functions, like the care for a particular local festival, could be given by tradition to a certain family. To a large extent, in the absence of "scriptural" sacred texts, religious practices derived their authority from tradition, and "every omission or deviation arouses deep anxiety and calls forth sanctions".
Greek ceremonies and rituals were mainly performed at altars. These were typically devoted to one or a few gods, and supported a statue of the particular deity. Votive deposits would be left at the altar, such as food, drinks, as well as precious objects. Sometimes animal sacrifices would be performed here, with most of the flesh taken for eating, and the offal burnt as an offering to the gods. Libations, often of wine, would be offered to the gods as well, not only at shrines, but also in everyday life, such as during a symposium.
One ceremony was pharmakos, a ritual involving expelling a symbolic scapegoat such as a slave or an animal, from a city or village in a time of hardship. It was hoped that by casting out the ritual scapegoat, the hardship would go with it.
Worship in Greece typically consisted of sacrificing domestic animals at the altar with hymn and prayer. The altar was outside any temple building, and might not be associated with a temple at all. The animal, which should be perfect of its kind, is decorated with garlands and the like, and led in procession to the altar, a girl with a basket on her head containing the concealed knife leading the way. After various rituals the animal is slaughtered over the altar, as it falls all the women present "must cry out in high, shrill tones". Its blood is collected and poured over the altar. It is butchered on the spot and various internal organs, bones and other inedible parts burnt as the deity's portion of the offering, while the meat is removed to be prepared for the participants to eat; the leading figures tasting it on the spot. The temple usually kept the skin, to sell to tanners. That the humans got more use from the sacrifice than the deity had not escaped the Greeks, and is often the subject of humour in Greek comedy.
The animals used are, in order of preference, bull or ox, cow, sheep (the most common), goat, pig (with piglet the cheapest mammal), and poultry (but rarely other birds or fish). Horses and asses are seen on some vases in the Geometric style (900-750 BC), but are very rarely mentioned in literature; they were relatively late introductions to Greece, and it has been suggested that Greek preferences in this matter go very far back. The Greeks liked to believe that the animal was glad to be sacrificed, and interpreted various behaviours as showing this. Divination by examining parts of the sacrificed animal was much less important than in Roman or Etruscan religion, or Near Eastern religions, but was practiced, especially of the liver, and as part of the cult of Apollo. Generally, the Greeks put more faith in observing the behaviour of birds.
For a smaller and simpler offering, a grain of incense could be thrown on the sacred fire, and outside the cities farmers made simple sacrificial gifts of plant produce as the "first fruits" were harvested. The libation, a ritual pouring of fluid, was part of everyday life, and libations with a prayer were often made at home whenever wine was drunk, with just a part of the cup's contents, the rest being drunk. More formal ones might be made onto altars at temples, and other fluids such as olive oil and honey might be used. Although the grand form of sacrifice called the hecatomb (meaning 100 bulls) might in practice only involve a dozen or so, at large festivals the number of cattle sacrificed could run into the hundreds, and the numbers feasting on them well into the thousands.
The evidence of the existence of such practices is clear in some ancient Greek literature, especially in Homer's epics. Throughout the poems, the use of the ritual is apparent at banquets where meat is served, in times of danger or before some important endeavor to gain the favor of the gods. For example, in Homer's Odyssey Eumaeus sacrifices a pig with prayer for his unrecognizable master Odysseus. However, in Homer's Iliad, which partly reflects very early Greek civilization, not every banquet of the princes begins with a sacrifice.
These sacrificial practices share much with recorded forms of sacrificial rituals known from later. Furthermore, throughout the poem, special banquets are held whenever gods indicated their presence by some sign or success in war. Before setting out for Troy, this type of animal sacrifice is offered. Odysseus offers Zeus a sacrificial ram in vain. The occasions of sacrifice in Homer's epic poems may shed some light onto the view of the gods as members of society, rather than as external entities, indicating social ties. Sacrificial rituals played a major role in forming the relationship between humans and the divine.
It has been suggested that the Chthonic deities, distinguished from Olympic deities by typically being offered the holocaust mode of sacrifice, where the offering is wholly burnt, may be remnants of the native Pre-Hellenic religion and that many of the Olympian deities may come from the Proto-Greeks who overran the southern part of the Balkan Peninsula in the late third millennium BC.
Various religious festivals were held in ancient Greece. Many were specific only to a particular deity or city-state. For example, the festival of Lykaia was celebrated in Arcadia in Greece, which was dedicated to the pastoral god Pan. Like the other Panhellenic Games, the ancient Olympic Games were a religious festival, held at the sanctuary of Zeus at Olympia. Other festivals centred on Greek theatre, of which the Dionysia in Athens was the most important. More typical festivals featured a procession, large sacrifices and a feast to eat the offerings, and many included entertainments and customs such as visiting friends, wearing fancy dress and unusual behaviour in the streets, sometimes risky for bystanders in various ways. Altogether the year in Athens included some 140 days that were religious festivals of some sort, though varying greatly in importance.
In Ancient Greece, the only public roles that Greek women could perform were priestesses. As a priestess, they gained social recognition and access to more luxuries than other Greek women that worked or typically stayed in the home. Women who voluntarily chose to become priestesses received an increase in social and legal status to the public, and after death, they received a public burial site. Greek woman priests; Hiereiai means sacred women or in general terms, Amphipolis; meaning attendant had to be healthy and of a sound mind. The reasoning being that the ones serving the gods had to have as high of quality as their offerings, this was the same for Greek male priests.
It is contested whether there were gendered divisions when it came to serving a particular god or goddess, who was devoted to what god, gods and/or goddesses could have both priests and priestesses to serve them. Gender specifics did come into play when it came to who would perform certain acts of sacrifice or worship were determined by the significance of the male or female role to that particular god or goddess, a priest would lead the priestess or the reverse. In some Greek cults Priestesses served both gods and goddesses, such examples as the Oracle of Apollo at Delphi and Didyma were priestesses, but both were overseen by male priests. The festival of Dionosyus was practiced by both and the god was served by women and female priestesses, they were known as the Gerarai or the venerable ones. Any woman that served under Apollo at Delphi was known as the Prophets or the Pythia, and as with other cults the women priests were chosen and accepted because of their femininity. The Oracle of Delphi had to be young, inexperienced and have the female excitement, these girls often came from poor farming families.
There were segregated religious festivals in Ancient Greece;Thesmophoria, Plerosia, Kalamaia, and Skira, which were women only. The festival Thesmophoria and many others were to represent agricultural fertility that was considered to be closely connected to women by the ancient Greeks. It gave women a religious identity and purpose in Greek religion, in which the role of women in worshipping goddesses Demeter and her daughter Persephone reinforces traditional lifestyles. The festivals relating to agricultural fertility were valued by the Polis because this is what they traditionally worked for, women-centered festivals that involved private matters were less important. In Athens the festivals honoring Demeter were included in the calendar and promoted by Athens, they constructed temples and shrines like the Thesmophorion were women could perform their rites and worship.
The main Greek temple building sat within a larger precinct or temenos, usually surrounded by a peribolos fence or wall; the whole is usually called a "sanctuary". The Acropolis of Athens is the most famous example, though this was apparently walled as a citadel before a temple was ever built there. The tenemos might include many subsidiary buildings, sacred groves or springs, animals dedicated to the deity, and sometimes people who had taken sanctuary from the law, which some temples offered, for example to runaway slaves.
The earliest Greek sanctuaries probably lacked temple buildings, though our knowledge of these is limited, and the subject is controversial. A typical early sanctuary seems to have consisted of a tenemos, often around a sacred grove, cave or spring, and perhaps defined only by marker stones at intervals, with an altar for offerings. Many rural sanctuaries probably stayed in this style, but the more popular were gradually able to afford a building to house a cult image, especially in cities. This process was certainly under way by the 9th century, and probably started earlier.
The temple interiors did not serve as meeting places, since the sacrifices and rituals dedicated to the respective deity took place outside them, at altars within the wider precinct of the sanctuary, which might be large. As the centuries past both the inside of popular temples and the area surrounding them accumulated statues and small shrines or other buildings as gifts, and military trophies, paintings and items in precious metals, effectively turning them into a type of museum.
Some sanctuaries offered oracles, people who were believed to receive divine inspiration in answering questions put by pilgrims. The most famous of these by far was the female priestess called the Pythia at the Temple of Apollo at Delphi, and that of Zeus at Dodona, but there were many others. Some dealt only with medical, agricultural or other specialized matters, and not all represented gods, like that of the hero Trophonius at Livadeia.
The temple was the house of the deity it was dedicated to, who in some sense resided in the cult image in the cella or main room inside, normally facing the only door. The cult image normally took the form of a statue of the deity, typically roughly life-size, but in some cases many times life-size. In early days these were in wood, marble or terracotta, or in the specially prestigious form of a chryselephantine statue using ivory plaques for the visible parts of the body and gold for the clothes, around a wooden framework. The most famous Greek cult images were of this type, including the Statue of Zeus at Olympia, and Phidias's Athena Parthenos in the Parthenon in Athens, both colossal statues, now completely lost. Fragments of two chryselephantine statues from Delphi have been excavated. Bronze cult images were less frequent, at least until Hellenistic times. Early images seem often to have been dressed in real clothes, and at all periods images might wear real jewellery donated by devotees.
The acrolith was another composite form, this time a cost-saving one with a wooden body. A xoanon was a primitive and symbolic wooden image, perhaps comparable to the Hindu lingam; many of these were retained and revered for their antiquity, even when a new statue was the main cult image. Xoana had the advantage that they were easy to carry in processions at festivals. The Trojan Palladium, famous from the myths of the Epic Cycle and supposedly ending up in Rome, was one of these.
Many of the Greek statues well known from Roman marble copies were originally temple cult images, which in some cases, such as the Apollo Barberini, can be credibly identified. A very few actual originals survive, for example, the bronze Piraeus Athena (2.35 m (7.7 ft) high, including a helmet). The image stood on a base, from the 5th century often carved with reliefs.
It used to be thought that access to the cella of a Greek temple was limited to the priests, and it was entered only rarely by other visitors, except perhaps during important festivals or other special occasions. In recent decades this picture has changed, and scholars now stress the variety of local access rules. Pausanias was a gentlemanly traveller of the 2nd-century AD who declares that the special intention of his travels around Greece was to see cult images, and usually managed to do so.
It was typically necessary to make a sacrifice or gift, and some temples restricted access either to certain days of the year, or by class, race, gender (with either men or women forbidden), or even more tightly. Garlic-eaters were forbidden in one temple, in another women unless they were virgins; restrictions typically arose from local ideas of ritual purity or a perceived whim of the deity. In some places visitors were asked to show they spoke Greek; elsewhere Dorians were not allowed entry. Some temples could only be viewed from the threshold. Some temples are said never to be opened at all. But generally Greeks, including slaves, had a reasonable expectation of being allowed into the cella. Once inside the cella it was possible to pray to or before the cult image, and sometimes to touch it; Cicero saw a bronze image of Heracles with its foot largely worn away by the touch of devotees. Famous cult images such as the Statue of Zeus at Olympia functioned as significant visitor attractions.
Here, they could find religious consolations that traditional religion could not provide: a chance at mystical awakening, a systematic religious doctrine, a map to the afterlife, a communal worship, and a band of spiritual fellowship.
Some of these mysteries, like the mysteries of Eleusis and Samothrace, were ancient and local. Others were spread from place to place, like the mysteries of Dionysus. During the Hellenistic period and the Roman Empire, exotic mystery religions became widespread, not only in Greece, but all across the empire. Some of these were new creations, such as Mithras, while others had been practiced for hundreds of years before, like the Egyptian mysteries of Osiris.
Mainstream Greek religion appears to have developed out of Proto-Indo-European religion and although very little is known about the earliest periods there are suggestive hints that some local elements go back even further than the Bronze Age or Helladic period to the farmers of Neolithic Greece. There was also clearly cultural evolution from the Late Helladic Mycenaean religion of the Mycenaean civilization. Both the literary settings of some important myths and many important sanctuaries relate to locations that were important Helladic centres that had become otherwise unimportant by Greek times.
The Mycenaeans perhaps treated Poseidon, to them a god of earthquakes as well as the sea, as their chief deity, and forms of his name along with several other Olympians are recognisable in records in Linear B, although Apollo and Aphrodite are absent. Only about half of the Mycenaean pantheon seem to survive the Greek Dark Ages though. The archaeological evidence for continuity in religion is far clearer for Crete and Cyprus than the Greek mainland.
Greek religious concepts may also have absorbed the beliefs and practices of earlier, nearby cultures, such as Minoan religion, and other influences came from the Near East, especially via Cyprus.Herodotus, writing in the 5th century BC, traced many Greek religious practices to Egypt.
The Great Goddess hypothesis, that a Stone Age religion dominated by a female Great Goddess was displaced by a male-dominated Indo-European hierarchy, has been proposed for Greece as for Minoan Crete and other regions, but has not been in favour with specialists for some decades, though the question remains too poorly-evidenced for a clear conclusion; at the least the evidence from Minoan art shows more goddesses than gods. The Twelve Olympians, with Zeus as sky father, certainly have a strong Indo-European flavour; by the epic works of Homer all are well-established, except for Dionysus. However, several of the Homeric hymns, probably composed slightly later, are dedicated to him.
Archaic and Classical Greece saw the development of flourishing cities and of stone-built temples to the gods, which were rather consistent in design across the Greek world. Religion was closely tied to civic life, and priests were mostly drawn from the local elite. Religious works led the development of Greek sculpture, though apparently not the now-vanished Greek painting. While much religious practice was, as well as personal, aimed at developing solidarity within the polis, a number of important sanctuaries developed a "Panhellenic" status, drawing visitors from all over the Greek world. These served as an essential component in the growth and self-consciousness of Greek nationalism.
The mainstream religion of the Greeks did not go unchallenged within Greece. As Greek philosophy developed its ideas about ethics, the Olympians were bound to be found wanting. Several notable philosophers criticised a belief in the gods. The earliest of these was Xenophanes, who chastised the human vices of the gods as well as their anthropomorphic depiction. Plato wrote that there was one supreme god, whom he called the "Form of the Good", and which he believed was the emanation of perfection in the universe. Plato's disciple, Aristotle, also disagreed that polytheistic deities existed, because he could not find enough empirical evidence for it. He believed in a Prime Mover, which had set creation going, but was not connected to or interested in the universe.
In the Hellenistic period between the death of Alexander the Great in 323 BC and the Roman conquest of Greece (146 BC) Greek religion developed in various ways, including expanding over at least some of Alexander's conquests. The new dynasties of diadochi, kings and tyrants often spent lavishly on temples, often following Alexander in trying to insinuate themselves into religious cult; this was much easier for the Ptolemaic dynasty of Egypt, where the traditional ancient Egyptian religion had long had deified monarchs. The enormous raised Pergamon Altar (now in Berlin) and the Altar of Hieron in Sicily are examples of unprecedentedly large constructions of the period.
New cults of imported deities such as Isis from Egypt, Atargatis from Syria, and Cybele from Anatolia became increasingly important, as well as several philosophical movements such as Platonism, stoicism, and Epicureanism; both tended to detract from the traditional religion, although many Greeks were able to hold beliefs from more than one of these groups. Serapis was essentially a Hellenistic creation, if not devised then spread in Egypt for political reasons by Ptolemy I Soter as a hybrid of Greek and local styles of deity. Various philosophical movements, including the Orphics and Pythagoreans, began to question the ethics of animal sacrifice, and whether the gods really appreciated it; from the surviving texts Empedocles and Theophrastus (both vegetarians) were notable critics.Hellenistic astrology developed late in the period, as another distraction from the traditional practices. Although the traditional myths, festivals and beliefs all continued, these trends probably reduced the grip on the imagination of the traditional pantheon, especially among the educated, but probably more widely in the general population.
When the Roman Republic conquered Greece in 146 BC, it took much of Greek religion (along with many other aspects of Greek culture such as literary and architectural styles) and incorporated it into its own. The Greek gods were equated with the ancient Roman deities; Zeus with Jupiter, Hera with Juno, Poseidon with Neptune, Aphrodite with Venus, Ares with Mars, Artemis with Diana, Athena with Minerva, Hermes with Mercury, Hephaestus with Vulcan, Hestia with Vesta, Demeter with Ceres, Hades with Pluto, Tyche with Fortuna, and Pan with Faunus. Some of the gods, such as Apollo and Bacchus, had earlier been adopted by the Romans. There were also many deities that existed in the Roman religion before its interaction with Greece that were not associated with a Greek deity, including Janus and Quirinus.
The Romans generally did not spend much on new temples in Greece, other that those for their Imperial cult, which were placed in all important cities. Exceptions include Antoninus Pius (r. 138-161 AD), whose commissions include the Baalbec Temple of Bacchus, arguably the most impressive survival from the imperial period (though the Temple of Jupiter-Baal next to it was larger). It could be said the Greek world was by this time well furnished with sanctuaries. Roman governors and emperors often pilfered famous statues from sanctuaries, sometimes leaving contemporary reproductions in their place. Verres, governor of Sicily from 73 to 70 BC, was an early example who, unusually, was prosecuted after his departure.
After the huge Roman conquests beyond Greece, new cults from Egypt and Asia became popular in Greece as well as the western empire.
The initial decline of Greco-Roman polytheism was due in part to its syncretic nature, assimilating beliefs and practices from a variety of foreign religious traditions as the Roman Empire expanded. Graeco-Roman philosophical schools incorporated elements of Judaism and Early Christianity, and mystery religions like Christianity and Mithraism also became increasingly popular. Constantine I became the first Roman Emperor to convert to Christianity, and the Edict of Milan in 313 AD enacted official tolerance for Christianity within the Empire. Still, in Greece and elsewhere, there is evidence that pagan and Christian communities remained essentially segregated from each other, with little cultural influence flowing between the two. Urban pagans continued to utilize the civic centers and temple complexes, while Christians set up their own, new places of worship in suburban areas of cities. Contrary to some older scholarship, newly converted Christians did not simply continue worshiping in converted temples; rather, new Christian communities were formed as older pagan communities declined and were eventually suppressed and disbanded.
The Roman Emperor Julian, a nephew of Constantine who had been raised Christian, initiated an effort to end the suppression of non-Christian religions and re-organize a syncretic version of Graeco-Roman polytheism which he termed "Hellenism". Julian's Christian training influenced his decision to create a single organized version of the various old pagan traditions, with a centralized priesthood and a coherent body of doctrine, ritual, and liturgy based on Neoplatonism. Julian's successor Constantinus reversed some of his reforms, but Jovian,Valentinian I, and Valens continued Julian's policy of religious toleration towards both pagans and Christians in the Empire, and pagan writers applauded both for their policies.
Official persecution of paganism in the Eastern Empire began under Theodosius I in 381 AD. Theodosius strictly enforced anti-pagan laws, had priesthoods disbanded and temples destroyed, and actively participated in Christian actions against pagan holy sites. He enacted laws that prohibited worship of pagan gods not only in public, but also within private homes. The last Olympic Games were held in 393 AD, and Theodosius likely suppressed any further attempts to hold the games.
Western Empire Emperor Gratian, under the influence of his adviser Ambrose, ended the widespread, unofficial tolerance that had existed in the Western Roman Empire since the reign of Julian. In 382 AD, Gratian appropriated the income and property of the remaining orders of pagan priests, removed altars, and confiscated temples. Pagan senators argued that Gratian was ignoring his duty as Pontifex Maximus to ensure that rites to the Graeco-Roman gods continued to be performed, and Gratian responded by abdicating that title.
Despite official suppression of the ancient Graeco-Roman religion by the Roman government, its practice may have persisted in rural and remote regions into the early Middle Ages. A claimed temple to Apollo, with a community of worshipers and associated sacred grove, survived at Monte Cassino until 529 AD, when it was forcefully converted to a Christian chapel by Saint Benedict of Nursia, who destroyed the altar and cut down the grove. Other pagan communities, namely the Maniots, persisted in the Mani Peninsula of Greece until at least the 9th century.
Greek religion and philosophy have experienced a number of revivals, firstly in the arts, humanities and spirituality of Renaissance Neoplatonism, which was certainly believed by many to have effects in the real world. During the period of time (14th - 17th centuries) when the literature and philosophy of the ancient Greeks gained widespread appreciation in Europe, this new popularity did not extend to ancient Greek religion, especially the original theist forms, and most new examinations of Greek philosophy were written within a solidly Christian context.
Early revivalists, with varying degrees of commitment, were the Englishmen John Fransham (1730 - 1810), interested in Neoplatonism, and Thomas Taylor (1758 - 1835), who produced the first English translations of many Neoplatonic philosophical and religious texts.
More recently, a revival has begun with the contemporary Hellenism, as it is often called (a term first used by the last pagan Roman emperor Julian). In Greece, the term used is Hellene ethnic religion (Greek: ). Modern Hellenism reflects Neoplatonic and Platonic speculation (which is represented in Porphyry, Libanius, Proclus, and Julian), as well as classical cult practice. However, there are many fewer followers than Greek Orthodox Christianity. According to estimates reported by the U.S. State Department, there are perhaps as many as 2,000 followers of the ancient Greek religion out of a total Greek population of 11 million; however, Hellenism's leaders place that figure at 100,000 followers.