but was at the time a pejorative "catch-all word for non-Fur, Arab, non-Dinka and non-Luo groups of Western Bahr El Ghazal". Darfur historian Rex Sean O'Fahey describes the dynamic frontiers as follows: "it was not so much a place but rather a state of mind. As the slave raiders moved southwards, so Dar Fartit moved south."From the south-western side, meanwhile, the people in Dar Fertit came under pressure from systematic raids by Zande chieftains and kings. Turkiya (1821-1884/5) The Sudanese historian Ahmed Sikainga describes the impact that the Egyptian-Ottoman conquest of the Funj Kingdom in 1821 had on the lands of Dar Fertit as follows:"It represented the first large-scale efforts to draw the Nilotic regions into the expanding capitalist economy. Following the opening of the White Nile waters for navigation in the early 1840s, bands of European, Levantine, and northern Sudanese traders began to rush to the South. Eager to appropriate the resources of these virgin lands, these traders dominated the region by combining military power, political alliances, slave incorporation, and the judicious organization known as the zariba system. An Arabic word meaning 'thorned enclosure', the zariba in the Sudanese context referred to the small fortified settlements that were erstablished by the traders." The Northern Sudanese merchant Al-Zubeir Rahma Mansur first came to Bahr El Ghazal in 1856 with a cousin on a mission for the major trader Ali Amuriyy, since the Egyptian government had been monopolising trade in Northern Sudan, which encouraged commercial expansion beyond the state control into the South. Zachary Berman argues that Zubeir was an imperialist "buccaneer" following the market as an archetypical agent, "however unconsciously, of broader global market forces expressing themselves in Bahr al-Ghazal", namely Great Britain and France through Egypt. At first he went for ivory, ostrich feathers and gum arabic, which were greatly demanded luxury goods in Europe. However, like other merchants, he found that profits were not sufficient for the required capital of his own company and hence ventured into slave trading. In 1865, Zubeir's army of slaves killed a local king called Adoo Shukoo and took control of his small territory, transforming the merchant into a monarch. Johnson stresses the strategic importance of the location "where the north-south caravan route from Dar Fartit to Zandeland joined the east-west route to the Nile via Wau, Meshra el-Rek, Rumbek, and Shambe". Lawrence Mire also argues that this critical location allowed him to