What he has to tell us of the history of Southern Palestine was derived from oral tradition. He appears familiar with the region around Gaza, and mentions having seen Bishop Zeno of Majuma, the seaport of Gaza.
Sozomen wrote that his grandfather lived at Bethelia, near Gaza, and became a Christian together with his household, probably under Constantius II. A neighbor named Alaphrion was miraculously healed by Saint Hilarion who cast out a demon from Alaphrion, and, as eyewitnesses to the miracle, his family converted, along with Alaphrion's. The conversion marked a turning-point in the Christianization of southern Palestine, according to his account.
The grandfather became within his own circle a highly esteemed interpreter of Scripture. The descendants of the wealthy Alaphrion founded churches and convents in the district, and were particularly active in promoting monasticism. Sozomen himself had conversed with one of these, a very old man. He tells us that he was brought up under monkish influences and his history bears him out.
Sozomen seems to have been brought up in the circle of Alaphrion and acknowledges a debt of gratitude to the monastic order. His early education was directed by the monks in his native place. It is impossible to ascertain what curriculum he followed in these monastic schools, but his writings give clear evidence of the thoroughness with which he was grounded in Greek studies.
As a man he retained the impressions of his youth, and his great work later was to be also a monument of his reverence for the monks in general and for the disciples of Hilarion in particular.
As an adult he acquired training as a lawyer. He studied law in Beirut. He then went to Constantinople to start his career as a lawyer, perhaps at the court of Theodosius II. While thus engaged he conceived, around the year 443 the project of writing a history of the Church.
Sozomen wrote two works on church history, of which only the second one is extant.
His first work covered the history of the Church, from the Ascension of Jesus to the defeat of Licinius in 323, in twelve books. His sources for it included Eusebius of Caesarea, the Clementine homilies, Hegesippus, and Sextus Julius Africanus.
Sozomen's second work continues approximately where his first work left off. He wrote it in Constantinople, around the years 440 to 443 and dedicated it to Emperor Theodosius II.
The work is structured into nine books, roughly arranged along the reigns of Roman Emperors:
Book IX is incomplete. In his dedication of the work, he states that he intended cover up to the 17th consulate of Theodosius II, that is, to 439. The extant history ends about 425. Scholars disagree on why the end is missing. Albert Guldenpenning supposed that Sozomen himself suppressed the end of his work because in it he mentioned the Empress Aelia Eudocia, who later fell into disgrace through her supposed adultery. However, it appears that Nicephorus, Theophanes, and Theodorus Lector did read the end of Sozomen's work, according to their own histories later. Therefore, most scholars believe that the work did actually come down to that year, and that consequently it has reached us only in a damaged condition.
According to historian and scholar of Islam Michael Cook, Sozomen wrote that a group of "Saracens" (Arabs) in Palestine had adopted Jewish laws and customs after coming into contact with Jews, and who may have been (according to Cook) the forerunners of Islam and Muslims.
Sozomen borrowed heavily from other sources for his work.
The source for about three-fourths of his material was the writings of Socrates Scholasticus. The literary relationship of these writers appears everywhere. Valesius asserted that Sozomen read Socrates, and Robert Hussey and Guldenpenning have proved this. For example, Socrates, in I.x, relates an anecdote which he had heard, and says that neither Eusebius nor any other author reports it, yet this anecdote is found in Sozomen, I.xxii, the similarity of diction showing that the text of Socrates was the source.
The extent of this dependence cannot be accurately determined. Sozomen used the work of Socrates as a guide to sources and order. In some matters, such as in regard to the Novatians, Sozomen is entirely dependent on Socrates.
But Sozomen did not simply copy Socrates. He went back to the principal sources used by Socrates and other sources, often including more from them than Socrates did.
He used the writings of Eusebius, the first major Church historian. The Vita Constantini of Eusebius is expressly cited in the description of the vision of Constantine.
Sozomen appears also to have consulted the Historia Athanasii and also the works of Athanasius including the Vita Antonii. He completes the statements of Socrates from the Apologia contra Arianos, lix, sqq., and copies Athanasius' Adv. episcopos AEgypti, xviii-xix.
Rufinus is frequently used. Instructive in this respect is a comparison of Sozomen, Socrates, and Rufinus on the childhood of Athanasius. Rufinus is the original; Socrates expressly states that he follows Rufinus, while Sozomen knows Socrates' version, but is not satisfied with it and follows Rufinus more closely.
The ecclesiastical records used by Sozomen are principally taken from Sabinus, to whom he continually refers. In this way he uses records of the synods from that of Tyre (335) to that of Antioch in Caria (367).
For the period from Theodosius I, Sozomen stopped following the work of Socrates and followed Olympiodorus of Thebes, who was probably Sozomen's only secular source. A comparison with Zosimus, who also made use of Olympiodorus, seems to show that the whole ninth book of Sozomen, is mostly an abridged extract from Olympiodorus.
Sozomen used many other authorities. These include sources relating to Christianity in Persia, monkish histories, the Vita Martini of Sulpicius Severus, the works of Hilarius, logoi of Eustathius of Antioch, the letter of Cyril of Jerusalem to Constantius concerning the miraculous vision of the cross, and Palladius.
He also used oral tradition, adding some of the most distinctive value to his work.
A noteworthy edition was done by Valesius (Cambridge, 1720), who used, besides the text of Stephens, a Codex Fucetianus (now at Paris, 1445), "Readings" of Savilius, and the indirect traditions of Theodorus Lector and of Cassiodorus-Epiphanius.
Hussey's posthumous edition (largely prepared for the press by John Barrow, who wrote the preface) is important, since in it the archetype of the Codex Regius, the Codex Baroccianus 142, is collated for the first time. But this manuscript was written by various hands and at various times and therefore is not equally authoritative in all its parts.
There is an excellent English translation published in 1846 (London, Samuel Bagster and sons), translator unnamed, later reprinted and credited to Chester David Hartranft (1839-1914), with a learned though somewhat diffuse introduction, in the Nicene and Post-Nicene Fathers, II (published New York, 1890). (This text is available on-line at the Christian Classics Ethereal Library.)
On ethnic identity and ecclesiastical politics in Sozomen, see: Argov, Eran I. (2005). "A Church Historian in Search of an Identity: Aspects of Early Byzantine Palestine in Sozomen's Historia Ecclesiastica". Zeitschrift für Antikes Christentum. 9: 367-396.
The English translation of the Ecclesiastical History ascribed to Chester D. Hartranft is available online:
The English translation of the Ecclesiastical History by Edward Walford as originally published in the Bohn Ecclesiastical Library, is available in book form: