evidence: About 200 armed Filipinos, followers of Jamalul Kiram III, the self-proclaimed Sultan of Sulu, entered a town in Lahad Datu district of Malaysia’s Sabah state on February 11, sparking an ongoing conflict with Malaysian security forces that has tensions running high on both sides of Sulu Sea. The men, led by the sultan’s brother, are pressing their ancestral claim to an area of northern Borneo that has been disputed by Malaysia and the Philippines since independence. [...] A2: According to tradition, the Sultanate of Brunei ceded much of northern Borneo to the then-independent Sultanate of Sulu in the late 17th century in exchange for aid given during a civil war in Brunei. Sulu’s influence waxed and waned in the area until it was conquered by Spain in 1851. Given the overlapping claims of Brunei and Sulu to northern Borneo, the British North Borneo Company signed agreements with both sultanates in 1877 and 1878 ceding responsibility for the area to the company. [...] Meanwhile, the Philippine government has long questioned the legality of the British North Borneo Company’s agreement with Sulu passing to Malaysia. Manila instead insists that the title to northern Borneo should more properly have passed to the Philippines, of which Sulu is a part.