Church-Building and Charity
Marcian's most lasting work was the construction and adornment of churches in Constantinople. He built a church dedicated to the Martyr Anastasia, richly adorned it, and arranged for the transfer of the saint's relics to it; he also built a church of the Great Martyr Irene and a church of Saint Isidore. More broadly he is said to have built or repaired a large number of churches in the capital in a stately manner.
From the same wealth he distributed generous alms, much of it given quietly, and was noted for non-covetousness and self-denial. Tradition recalls that from childhood he had given himself to vigil, fasting, and prayer in imitation of Saint John the Baptist, and that as a presbyter he made the relief and instruction of the poor his chief occupation.