the bagirmi carried a tradition that they migrated from far to the east, which is supported by the resemblance of their language to various tribes on the white nile. it is not entirely clear when and by whom bagirimi kingdom was founded: some king lists trace this event to 1480, when it was supposedly founded by mbang abd al-mahmud begli, while others deem mbang birni besse responsible, who is said to have founded the kingdom in 1522. he seems to have displaced the earlier bulala, while he also began to build a palace in massenya, the capital of the state. the fourth king, abdullah (1568–1608), adopted islam and converted the state into a sultanate, permitting the state to extend their authority over many pagan tribes in the area, including the area's saras, gaberi, somrai, gulla, nduka, nuba, and sokoro. he and his successors continued to use the title "mbang" alongside that of "sultan".