Captain Percival’s Sketch Map from his 1904 journey through Abyei. Percival was a British officer whose sketch maps were used to make the provincial maps of Bahr el Ghazal province. In December 1904, he proceeded south via Keilak and crossed what he thought was the Bahr el Arab, before fording another river, which he reported to be the Kiir, some fifty miles south. Because the court case this essay deals with was mandated to rule on whether the Abyei Boundaries Commission had exceeded its mandate (to determine the are of the nine Ngok Chiefdoms transferred to Kordofan in 1905), maps of the period became a crucial source of evidence.