to avenge Ahmed's death, who succeeded Imam Ahmad, and continued hostilities against his northern adversaries until he killed the Ethiopian Emperor in his second invasion of Ethiopia, Emir Nur died in 1567. The Portuguese, meanwhile, tried to conquer Mogadishu but according to Duarta Barbosa never succeeded in taking it. The Sultanate of Adal disintegrated into small independent states, many of which were ruled by Somali chiefs. British Somaliland The British Somaliland protectorate was initially ruled from British India (though later on by the Foreign Office and Colonial Office), and was to play the role of increasing the British Empire's control of the vital Bab-el-Mandeb strait which provided security to the Suez Canal and safety for the Empire's vital naval routes through the Red Sea and the Gulf of Aden. Resentment against the British authorities grew: Britain was seen as excessively profiting from the thriving coastal trading and farming occurring in the territory. Beginning in 1899, religious scholar Mohammed Abdullah Hassan began a campaign to wage a holy war. Hassan raised an army united through the Islamic faith and established the Dervish State, fighting Ethiopian, British, and Italian forces, at first with conventional methods but switching to guerilla tactics after the first clash with the British. The British launched four early expeditions against him, with the last one in 1904 ending in an indecisive British victory. A peace agreement was reached in 1905, and lasted for three years. British forces withdrew to the coast in 1909. In 1912 they raised a camel constabulary to defend the protectorate, but the Dervishes destroyed this in 1914. In the First World War the new Ethiopian Emperor Iyasu V reversed the policy of his predecessor, Menelik II, and aided the Dervishes, supplying them with weapons and financial aid. Germany sent Emil Kirsch, a mechanic, to assist the Dervish Forces as an armourer at Taleh from 1916–1917, and encouraged Ethiopia to aid the Dervishes while promising to recognise any territorial gains made by either of them. The Ottoman Empire sent a letter to Hassan in 1917 assuring him of support and naming him "Emir of the Somali nation". At the height of his power, Hassan led 6000 troops, and by November 1918 the British administration in Somaliland was spending its entire budget trying to stop Dervish activity. The Dervish state fell in February 1920 after a British campaign led by aerial bombing. Sporadic uprisings were to