The Fifth Expedition of the Somaliland campaign in 1920 was the final British expedition against the Dervish forces of Mohammed Abdullah Hassan, the Somali religious leader. Although most of the combat took place in January of the year, British troops had begun preparations for the assault as early as November 1919. The British forces included elements of the Royal Air Force and the Somaliland Camel Corps. After three weeks of battle, Hassan's Dervishes were defeated, bringing an effective end to their 20-year resistance.