King, or king regnant, is the title given to a male monarch in a variety of contexts. The female equivalent is queen regnant, while the title of queen on its own usually refers to the consort of a king.
The term king may also refer to a king consort, a title that is sometimes given to the husband of a ruling queen, but the title of prince consort is sometimes granted instead. A king dowager is the male equivalent of the queen dowager. A king father is a king dowager who is also the father of the reigning sovereign.
The English term king is derived from the Anglo-Saxon cyning, which in turn is derived from the Common Germanic *kuningaz. The Common Germanic term was borrowed into Estonian and Finnish at an early time, surviving in these languages as kuningas. The English term "King" translates, and is considered equivalent to, Latin r?x and its equivalents in the various European languages. The Germanic term is notably different from the word for "King" in other Indo-European languages (*r?ks "ruler"; Latin r?x, Sanskrit r?jan and Irish ríg, but see Gothic reiks and, e.g., modern German Reich and modern Dutch rijk). It is a derivation from the term *kunjom "kin" (Old English cynn) by the -inga- suffix. The literal meaning is that of a "scion of the [noble] kin", or perhaps "son or descendant of one of noble birth" (OED).
The English word is of Germanic origin, and historically refers to Germanic kingship, in the pre-Christian period a type of tribal kingship. The monarchies of Europe in the Christian Middle Ages derived their claim from Christianisation and the divine right of kings, partly influenced by the notion of sacral kingship inherited from Germanic antiquity.
The Early Middle Ages begin with a fragmentation of the former Western Roman Empire into barbarian kingdoms. In Western Europe, the kingdom of the Franks developed into the Carolingian Empire by the 8th century, and the kingdoms of Anglo-Saxon England were unified into the kingdom of England by the 10th century.
With the breakup of the Carolingian Empire in the 9th century, the system of feudalism places kings at the head of a pyramid of relationships between liege lords and vassals, dependent on the regional rule of barons, and the intermediate positions of counts (or earls) and dukes. The core of European feudal manorialism in the High Middle Ages were the territories of the former Carolingian Empire, i.e. the kingdom of France and the Holy Roman Empire (centered on the nominal kingdoms of Germany and Italy).
In the course of the European Middle Ages, the European kingdoms underwent a general trend of centralisation of power, so that by the Late Middle Ages there were a number of large and powerful kingdoms in Europe, which would develop into the great powers of Europe in the Early Modern period.
Currently (as of 2016sovereign states (i.e. English king is used as official translation of the respective native titles held by the monarchs).), fifteen kings are recognized as the heads of state of
|Harald V King of Norway||Glücksburg||konge||Kingdom of Norway||11th c.|
|Carl XVI Gustaf King of Sweden||Bernadotte||konung||Kingdom of Sweden||12th c.|
|Felipe VI King of Spain||Bourbon||rey||Kingdom of Spain||1978 / 1479|
|Willem-Alexander King of the Netherlands||Orange-Nassau||koning||Kingdom of the Netherlands||1815|
|Philippe King of the Belgians||Saxe-Coburg and Gotha||koning / roi||Kingdom of Belgium||1830|
|Salman King of Saudi Arabia||Saud||malik||Kingdom of Saudi Arabia||1932|
|Abdullah II King of Jordan||Hashim||malik||Hashemite Kingdom of Jordan||1946|
|Mohammed VI King of Morocco||Alaoui||malik||Kingdom of Morocco||1956|
|Hamad bin Isa Al Khalifa King of Bahrain||Khalifa||malik||Kingdom of Bahrain||1971|
|Vajiralongkorn King of Thailand||Chakri||kasat||Kingdom of Thailand||1782|
|Jigme Khesar Namgyel Wangchuck King of Bhutan||Wangchuck||druk gyalpo||Kingdom of Bhutan||1907|
|Norodom Sihamoni King of Cambodia||Norodom||sdac||Kingdom of Cambodia||1993 / 1953|
|Tupou VI King of Tonga||Tupou||king / tu'i||Kingdom of Tonga||1970|
|Letsie III King of Lesotho||Moshesh||king / morena||Kingdom of Lesotho||1966|
|Mswati III King of Eswatini||Dlamini||ngwenyama||Kingdom of Eswatini||1968|