The earliest monasteries in Christianity outside of Egypt were built in Palestine during this period, notably those of Hilarion near Gaza, Saint Epiphanius at Ad near the city of Eleutheropolis (Bayt Jibrin, the head of the largest bishopric in Palestine at this time), Tyrannius Rufinus and Melania the Elder on the Mount of Olives, Euthymius the Great at Pharan, Sabbas the Sanctified in the Kidron Valley as well as St. George's Monastery in Wadi al-Qelt, the Monastery of the Temptation and Deir Hajla near Jericho, and Deir Mar Saba and Deir Theodosius east of Bethlehem. The sack of Rome in 410 caused a significant episode of migration to Palestine as a group of aristocratic ladies responded to the holy man Jerome's invitation to settle in Aelia Capitolina and Bethlehem. In 451, the Council of Chalcedon confirmed Jerusalem's status as a Patriarchate as one of the Pentarchy, and Juvenal of Jerusalem became the first Patriarch of Jerusalem