Until the 1830s, the dominant purpose of European colonization in Africa was the slave trade. From 1808–34, the abolition movement progressively eliminated the European slave trade with North America, but the Islamic Sokoto caliphate did its best to compensate. Founded in 1804 by a Sufist rebellion, this confederation of emirates became one of Africa’s largest polities and second only to the American South in its slave population, exploiting the networks established by the defunct European traders. South America continued to be the main destination for the trans-Atlantic slave trade. While Britain’s Cape Colony steadily expanded, and the French were establishing dominion in Algeria and Senegal, the continent’s greatest conqueror of the period was Muhammad Ali Pasha in Egypt, annexing Nubia, Sudan and Libya before waging war upon his Ottoman overlords. After the abolition of the slave trade, the cargo changed but economic exploitation remained the heart of the enterprise, reaching peak intensity during the ‘Scramble for Africa’ initiated by the Treaty of Berlin (1885). The record of Christian missions through this period is chequered. Many performed a valuable educational function, and took the trouble to learn native languages, even producing the first written versions of them. The Methodist Robert Moffat, for instance, worked tirelessly with the Botswana and Ndebele in southern Africa, translating both the Bible and Pilgrim’s Progress, but an Anglican successor tricked the Ndebele king into signing away his kingdom to Cecil Rhodes. Presbyterian Mary Slessor worked to eliminate twin infanticide in Nigeria. The Catholic White Fathers were culturally tolerant, with missions from Tunisia to Uganda; however, Catholic missions in the Belgian Congo (and Lutherans in German Southwest Africa) did little to stem colonial repression. Despite European inroads into Africa, European nations only controlled 10 percent of the African continent in the 1870s, and their territories were overwhelmingly coastal. At the instigation of Portugal, the Berlin Conference was convened by the German Chancellor Otto von Bismarck, with 13 European powers and the United States represented. Its purpose was to establish a mutually agreed protocol for the colonization of Africa. The Conference reached an agreement regarding some existing conflicts between the participating powers. Resolutions passed were to end slavery on the continent, and assign the huge area of Congo Free State to Leopold II of Belgium. Most importantly, it established the ‘Principle of Effective Occupation’, with a colonizing power having to demonstrate some form of political and administrative control. This provision acted as an accelerant for the ‘Scramble for Africa’, which followed the conference, as colonial powers previously content with coastal trading bases rushed to claim dominion over vast territories in accordance with the Principle. Britain was the most ubiquitous colonial nation in Africa, with Cecil Rhodes (‘I would annex planets if I could’) carrying out a concerted land grab from the south, while a network of British protectorates in the north stretched from Egypt to Zanzibar. Zanzibar was also home to the clove plantations of its Sultan’s right-hand man, ivory and slave trader extraordinaire Tippu Tip, who met, and double-crossed, both Stanley and Livingstone, and fought (unsuccessfully) the Belgian occupation of the Congo (1892–94). Germany’s Bismarck, a new convert to colonialism, muscled in with fervour, garnering an approximation of modern Tanzania in return for recognizing British precedence in Uganda. Germany also staked a claim to Cameroon, while France, more active further north ushered in its ultimately vast equatorial colony with Gabon (1885). Straggling Italy was humiliatingly thrashed by Ethiopia at Adwa (1896) and had to content itself with Eritrea. Many African nations and peoples tried to resist the European takeover, including the Ashanti, Moroccans, Ethiopians, Dervishes and Zulus. Despite some successes, such as the resounding Zulu victory at Isandlwana (1879) and the Ethiopian defeat of Italy in 1896, the Europeans’ advanced weapons, for example, machine guns, enabled them to overwhelm African armies. Over 90 percent of Africa had been claimed by a colonial power by 1914, with only Ethiopia and Liberia free of European control. Of this land area, well over 90 percent was assigned to what would become the Allied Powers. Of the Central Powers, Austria-Hungary held no African territory, while German possessions, in Togoland, Cameroon, East Africa and Southwest Africa were widely dispersed, and thus difficult to defend. Egypt was a special case; nominally it was part of the Ottoman Empire, which would ally with the Central Powers, but effectively it operated as a British protectorate. It also hosted the Suez Canal, which probably constituted the most important strategic asset on the continent. Because of the frantic pace of colonization, imperial control was often tenuous. The war would see several rebellions in Africa, as inhabitants sought to exploit the distraction of the conflict to win their freedom.