 Complete the following phrase:  In December 1914, the 8th Light Horse Regiment left Sydney for Egypt, arriving on the 1 February 1915. When the Australian infantry units were dispatched to Gallipoli, it was thought the terrain was unsuitable for mounted troops, and the light horse regiments remained in Egypt. However, heavy casualties amongst the Australian infantry battalions resulted in the deployment of the 3rd Light Horse Brigade as reinforcements in May 1915. On arrival, the regiment was attached to the New Zealand and Australian Division. The regiment was heavily involved in the 