Christians reached the shores of the Persian Gulf by the beginning of the fourth century. According to the Chronicle of Seert, Bishop David of Perat d'Maishan was present at the Council of Seleucia-Ctesiphon, around 325, and sailed as far as India. Gregory Bar Hebraeus, Chron. Eccles, 2.10 (v. 3, col. 28) indicates that David had earlier ordained one of the other bishops present at the Council. The monk Jonah is said to have established a monastery in the Persian Gulf "on the shores of the black island" in the middle of the fourth century. A Nestorian bishopric was established at Rev-ardashir, nearly opposite the island of Kharg, in Southern Persia, before the Council of Dadisho in AD 424.