A treaty fixes an annual delivery of 360 people from Nubia

Fighting resumed in 651 and an Arab force of five thousand under Abd Allah b. Sa'd marched on Old Dongola, the capital of Makuria, battering the cathedral with catapults. The peace that followed was set down as a covenant binding Nubians from the frontier of Aswan to the border of Alwa. Neither side would raid the other. Each could pass through the other's territory without settling in it. The Nubians would send back runaway slaves and Muslim fugitives, and would sweep, light and protect the mosque built in the courtyard of their capital. Every year they were to hand over 360 people to the governor at Aswan, male and female, the finest of the country, none of them elderly and none below puberty. Food, cloth and wine came back the other way. A scribe dated the text to Ramadan of the year thirty one. The arrangement held for roughly five hundred years.

Arab armies took Egypt in 642 and pushed south against the Christian kingdoms of the Upper Nile. Nubia fought hard and had little gold or grain worth seizing, so in 652 the two sides settled on terms. No Muslim would enter the country. In return Nubia would hand over a fixed number of enslaved people every year, receiving other goods in exchange. The agreement was called the Baqt and it appears to have held for several hundred years. Under its shelter the kingdoms of Makuria, whose capital stood at Dongola, and Alwa, centred on Soba near modern Khartoum, built cathedrals and monasteries at Faras, Qasr Ibrim, Sai and elsewhere and covered their walls with paintings. This is one of the oldest recorded arrangements in which an African state agreed to deliver human beings on a schedule as the price of being left alone, and it ran for centuries before any European ship reached the Atlantic coast.