H. Delehaye's work on Greek hagiography remains fundamental and a collection of his research on the Byzantine sources has long been called for. This volume assembles his articles on the Metaphrastes' compilation brought up to date by Fr. Halkin with a bibliographical addendum, and the first publication of the foundation typica of two important monasteries in Constantinople - a mine of religious and prosographical information on the city and its upper classes in the Paleologan period.