Righteous Peter, prince of the Golden Horde, who was baptised and founded a monastery at Rostov.
Saint Peter was a nephew of the khan of the Golden Horde who was moved by the preaching of Saint Cyril, bishop of Rostov, and received baptism. He settled in Rostov, where tradition relates that the Apostles Peter and Paul appeared to him and he founded a monastery in their honour. He took the monastic habit before his repose in 1290.
Feast day
On the New Calendar, Peter, Prince of the Horde is commemorated on June 30. Churches on the Old (Julian) Calendar keep the feast on July 13 of the civil calendar.
Also commemorated on June 30

Synaxis of the Holy Apostles
Great Feast, Σύναξις Αποστόλων
Synaxis of the Glorious and All-Praised Twelve Apostles.