Later the Divisional Squadron of the D.L.O. Yeomanry rejoined the Division, and the 3rd Dismounted Brigade, mainly Yeomanry, was also attached. It is unnecessary to refer to the importance of the Suez Canal, not merely to the commerce of the Empire, but also to the policy and strategy of the Allies. But it may be well to explain here, very briefly and roughly, the general situation so far as it affected the defence of this main communication between East and West. Prior to the outbreak of war there were British frontier posts in Sinai as far east as El Arish on the coast about ninety miles due east of Port Said, and more than a hundred miles by road from the Canal. The sole purpose of these posts was to supervise and regulate traffic between Egypt and the Turkish Empire, and as such traffic automatically ceased on the outbreak of war with Turkey, the handful of troops was withdrawn. The invasion of Gallipoli had compelled the Turks to abandon for a time any idea they may have entertained of conquering Egypt. Now, at the beginning of 1916, although the withdrawal of the Allies from the Dardanelles and the entry of Bulgaria into the war on the side of her ancient enemy had set free a large Turkish army for employment in Asia, the situation had not greatly changed. The heavy losses sustained in Gallipoli had been a serious drain upon the finest troops of the Ottoman Empire; the Russians had entered Armenia victoriously, and it was not possible for Turkey to prepare and equip new armies to arrest the Russian progress and at the same time to cross the Desert of Sinai with any reasonable prospect of success. For, if the evacuation of Gallipoli had released a large Turkish force for offensive purposes, it had done no less for the British, and the conquest of Egypt was still a remote possibility only. But, as the Turks had been improving their communications through Palestine, there remained the probability that they might attempt to establish themselves in strength within striking distance of the Canal. They hoped that a successful attack here might bring about a rebellion in Egypt. While the Egyptians remained passive spectators there was no chance of a Turkish victory. [Sidenote: _Routes open to Enemy_] There are three routes by which a hostile force might approach the Canal. (1) The northern caravan route along the coast through El Arish to Kantara, the route by which Joseph’s brethren, and later the Holy Family, and in more recent times Napoleon, had travelled from Palestine to Egypt. (2) The central Hassana—Ismailia route. (3) The southern Akaba—Suez route.