Saint Mamas is for modern people a relatively unknown saint, although he was martyred at a very young age (15 or 18 years old) in Caesarea, a great Christian center of Asia Minor, during the reign of Emperor Aurelian (270-275), and has been venerated since early Christian times. The earliest iconographic type of the Saint appears in Cappadocia: Saint Mamas depicted full length riding a lion with an upright tail striding to the right.
The veneration of Saint Mamas was transferred to Constantinople in the 5th century. By the second half of the 5th century, a suburb was already named after the Saint. In 469, Emperor Leo I found refuge there for six months, at the east side of the city (today Beşiktaş), during a conflagration in Constantinople. He built a palace, harbor, hippodrome, and a church dedicated to the Saint.
To the west of the city, close to Xylokerkos Gate (today Belgrad kapi), Justinian’s chambermaid Farasmanis, according to Zonaras, founded a monastery in honor of Saint Mamas; this was the monastery where Saint Symeon the New Theologian was abbot for 25 years. During the reign of the Emperor Isaac II Angelos (1185-1195), the monastery was rebuilt and the skull of Saint Mamas was placed there since it had been brought by a monk in 1067 after the fall of Caesarea to the Seljuk Turks.
Many scholars mention other monasteries and churches honoring the Saint’s name in Constantinople, but their locations remain unknown. The Saint was very popular in the Byzantine capital; according to the anonymous French pilgrim who brought relics of the Saint to the city of Langres on his return from Jerusalem, “no other Martyr’s name resounded as much among the people.” The dissemination of the Saint’s veneration is possibly related to the documented influx of Isaurian soldiers into Byzantium during the 5th-6th century.