(Εὐτυχιανός). There are two persons of this name in the history of Constantinople: the one is called an historian, and must have lived at the time of Constantine the Great. He is styled chief secretary of the emperor, and a sophist; but nothing further is known. (Georg. Codinus, Select. de Orig. Constant. 17.) The second was a friend of Agathius the historian, who undertook to write the history of his own time on the advice of Eutychianus. (Agath. Prooem.)
[L.S]A Dictionary of Greek and Roman biography and mythology
Smith, William
A Dictionary of Greek and Roman biography and mythology. William Smith, LLD, ed. 1890