The Baqt (or Bakt) was a treaty between the Christian state of Makuria and the Muslim rulers of Egypt. Lasting almost seven hundred years it is by some measures the longest lasting treaty in history. The name comes either from the Egyptian's term for barter or the Greco-Roman term for pact.
Despite its longevity not much is clear about the baqt and almost all the information about it comes from Muslim sources. The Baqt was signed after the 641 Muslim conquest of Egypt. That year Abdallah ibn Abi Sarh led an army south against the Christian kingdoms of Nubia. Later Islamic historians state that Nubia was not worth conquering and the expedition was simply to subordinate the region to Egypt. Earlier sources give the more likely story that the Arab armies met a rare defeat at the Battle of Dongola and only acceded to the Baqt when they realized that the conquest of the region would be difficult. The treaty was negotiated between Abi Sarh and the Makurian King Qalidurat.
There is no extant copy of the treaty they signed, and the earliest copies are several centuries after the fact and are quite varied. The treaty might not have been written at all and may have just been an oral agreement. Some sections of the baqt are clear:
The most important provision was that 360 slaves per year were to be sent to Egypt. These slaves had to be of the highest quality with no old ones or children; they were to be a mix of male and female. In some reports an extra forty were due which were distributed among notables in Egypt.
Ibn Abd al-Hakam, one of the first historians to discuss the treaty, gives two different versions of the treaty. The first has only Nubia sending slaves north, thus symbolizing its subservience to Egypt. The second version adds an obligation of the Egyptians to also send goods south including wheat and lentils in exchange for the slaves; this would put the two nations on a more equal footing.
This treaty was unprecedented in the history of the Arab conquests, being more similar to the arrangements the Byzantine Empire sometimes made with its neighbours. It is also unmatched in that it largely blocked the spread of Islam and the Arabs for half a millennium. The Baqt caused some controversy among Islamic theologians as there was disagreement over whether it violated the duty to expand the borders of Islam. Spaulding reports that the exchange of goods was a common diplomatic arrangement in Northeast Africa and the Nubians would have had long experience with such agreements.