Venerable Isaac of Dalmatia

Saint Isaac came "from the East", most likely from Syria, and lived as a hermit in the desert until, according to his Life, a voice from heaven sent him to Constantinople. He arrived during the reign of Emperor Valens (364–378), who favoured the Arians and persecuted the Orthodox.

In 378, as Valens set out against the Goths, Isaac repeatedly begged him to return the churches to the Orthodox. When the emperor refused, Isaac foretold his defeat and death by fire and was kept in custody. Valens was routed at Adrianople on 9 August 378 and burned to death in a building set alight by his pursuers; the church historians Theodoret and Sozomen also record the prophecy.

Theodosius the Great released Isaac and received him with honour. At the request of the officials Saturninus and Victor he stayed in the capital, living in a cell outside the walls; it grew into what is considered the oldest monastery of Constantinople, later named after his disciple and successor Dalmatus. His Life dates his death to 383, but scholars place it after 406.

In Russia he is honoured as the patron of Peter the Great, born on his feast day; St Isaac's Cathedral in St Petersburg is dedicated to him. Feast: 30 May (12 June); also 3 (16) August with Saints Dalmatus and Faustus.