The Persian religious figure Mani listed Axum with Rome, Persia, and China as one of the four great powers of his time.[45] It was in the early 4th century AD that a Syro-Greek castaway, Frumentius, was taken to the court and eventually converted King Ezana to Christianity, thereby making it the official state religion.[46] For this accomplishment, he received the title "Abba Selama" ("Father of peace"). At various times, including a period in the 6th century, Axum controlled most of modern-day Yemen and some of southern Saudi Arabia just across the Red Sea, as well as controlling northern Sudan, northern Ethiopia, Eritrea and Djibouti.[47]