Before 1840, the region that would become southern Sudan lay at the furthest limits of any long-distance commerce and beyond the reach of any state powers. Only its northernmost areas were already being raided for slaves for the markets and trade roads further north, while to the east were the distant frontiers of the Ethiopian kingdom, and to the south the kingdoms of Buganda and Bunyoro. The earliest documentary evidence is suggestive of some possible long-distance commercial linkages, notably demonstrated by the blue cloth worn by Bari rain chiefs on the Nile, which was said to have come from the east via Lafon hill. But such limited connections would be dramatically overtaken by the sudden advance of new imperial and commercial frontiers after 1840. This region became the southern frontier of Turco-Egyptian expansion under the Ottoman ruler of Egypt, Mohamed ‘Ali, and his grandson, Khedive Ismail. At the same time, East African trading networks were reaching the lacustrine kingdoms to the south, spreading the hunt for ivory and slaves northwards. European investment in Egypt would ultimately heighten British strategic concerns with the upper Nile, supported by the growing British public interest in the region generated by explorers and Christian missionaries and further stimulated by French and Belgian competition. By the end of the nineteenth century, it was European imperial frontiers that were colliding on the upper Nile, and by 1910 the southern Sudan was firmly incorporated into the British colonial sphere, as part of the Anglo-Egyptian Condominium of Sudan.