The five holy men and one holy woman presented in this volume represent five significant monastic figures from the years 370 to 470 whose Lives are not currently available in English translation. Isaac confronted Emperor Valens and predicted his death at Adrianople before accepting the patronage of Saturninus; Hypatius built up a community at a deserted monastery south of Chalcedon, which he led for four decades; Marcellus was the third leader of the ‘Sleepless’ monastery at Irenaeum on the Bosporus; Domnica established a female community outside the city with the support of the patriarch; Auxentius abandoned service in the imperial guards to take up residence on a hill south of Chalcedon, where he attracted both male and female devotees; and the sixth individual, John the Calybite, if he existed John the Calybite, if he existed, left the Sleepless community to place himself as a beggar outside his parents’ grand house in Constantinople, only revealing himself when near death. Their interactions, not always positive, with Constantinople’s religious and secular leadership, as well as their care for ordinary people, cast light on the life of the capital and the needs and beliefs of its inhabitants.