 In response to the growing threat from a pro-Turkish Islamic Arab sect known as the Senussi, a composite British force—the "Western Frontier Force"—under the command of the British Indian Army officer Major General Alexander Wallace, was sent into the Libyan Desert to Mersa Matruh in late-November 1915.This force included a composite regiment of Australian light horse and the horse transport of the 1st Division.A series of sharp battles against the Arabs ensued at Um Rakhum, Gebel Medwa and Halazin during December and January.