Christian tradition assigns the apostle Andrew a mission along the sea's southern and northern shores, and that claim became the foundation charter of more than one church: the ecumenical patriarchate of Constantinople traces its see to him, and Georgian and Russian traditions both invoke his journey. Whatever its historical basis, the sea was genuinely Christianised early, with bishoprics at the Greek ports and, in Crimea, at Chersonesus, where Byzantine sources place the baptism of Vladimir of Kiev in 988 before his marriage to the emperor's sister and the conversion of Rus.
Byzantium ruled the sea, then shared it with Genoese and Venetian merchant colonies, and lost it after 1453. The Ottomans closed it to foreign shipping and held it as an internal sea for three centuries, with the Crimean khanate as a vassal on the northern shore. Russian expansion from the eighteenth century turned it into a contested frontier, and the Crimean War of 1853 to 1856, which began in a quarrel over the holy places at Jerusalem, was fought largely to keep Russian power off it.
Charles King's history follows a sea whose ports have been repeatedly emptied and refilled: Greeks from Anatolia, Muslim Tatars from Crimea, Jews from Odesa. Its lower waters carry no oxygen below about two hundred metres, and shipwrecks with masts and rigging intact have been found preserved in that dead layer.