that regiment's 'B' Squadron; 'B' Squadron went to the 7th Light Horse Regiment at "Ryrie's Post", adopting the designation of 'D' Squadron; and 'C' Squadron went to the 6th Light Horse Regiment around "Holly Spur" and "Lone Pine", becoming their 'D' Squadron. The Regimental Headquarters was absorbed by the 3rd Light Horse Brigade's headquarters, while Abbott took command of the 10th Light Horse Regiment. For the remainder of the campaign, about 600 men from the regiment – including a batch of reinforcements that arrived in early October – carried out mainly defensive duties before leaving with the last Australian troops to be evacuated from the peninsula on 20 December. They did not take part in any large-scale battles, but were involved in fighting off a number of sharp attacks. The exact number of casualties suffered is not known, but 18 men from the regiment are known to have been killed in this time. Sinai Following their evacuation from Gallipoli, the regiment was reconstituted on 22 February 1916 when all three squadrons assembled at Heliopolis. Under a new commanding officer, Lieutenant Colonel John Royston – a veteran of the Boer War who had replaced Abbott after the latter had been sent to England – the regiment began to re-form. At the time of re-forming, it had been intended that the 12th would be assigned to the 5th Division as its divisional light horse regiment; however, it was decided to reduce the size of divisional light horse components to a squadron, and the 12th were removed from the 5th Division's order of battle. Although other units, such as part of the 4th and all of the 13th Light Horse Regiment, were sent to Europe to fight on the Western Front, the 12th, along with the bulk of the Australian light horse units, were to remain in the Middle East, where they would take part in the Sinai and Palestine campaign. Initially, the regiment was not brigaded and served as a detached unit. After conducting infantry training around Tel-el-Kebir in early April, the regiment crossed the Suez Canal along a new railway that was being constructed through the Sinai towards Palestine. Here it was established around Kantara and a position known as "Hill 70". The following month, Ottoman forces clashed with positions around the railhead and on 14 May, a British garrison was attacked at Dueidar, about away from the regiment's positions at