Socrates (born c. 380, Constantinople—died c. 450) was a Byzantine church historian whose annotated chronicle, Historia ecclesiastica (“Ecclesiastical History”), is an indispensable documentary source for Christian history from 305 to 439. Through excerpts from the 6th-century Latin translation ascribed to Cassiodorus and Epiphanius, it provided the medieval Latin church with a major portion of its knowledge of early Christianity.
A legal consultant, Socrates was the first known layman to write church history. The Historia ecclesiastica, the second edition of which is still completely extant, encompasses religious and secular annals of the period in seven books. Each book corresponds to the reign of an Eastern Roman emperor, from Constantine I (ad 306–337) to Theodosius II (408–450), and continues the church history of the 4th-century historian Eusebius of Caesarea. Incorporating earlier sources verbatim and integrating conciliar proceedings with available letters of emperors and bishops, Socrates compiled a relatively impartial account of events that he sometimes embellished with expanded anecdotes from eyewitnesses.