 Complete the following phrase:  Sustained fighting began in the early hours and by about 11:00 on 4 August, the Austrian, German and Ottoman force had pushed the two Australian brigades back to a point where the 52nd Lowland Division in their trenches were able to attack the attackers right flank, and the New Zealand Mounted Rifle and 5th Mounted Brigades arrived in time to extend the Australian Light Horses line. The Ottoman advance was stopped by the combined Allied fire from the infantry and mounted troops, deep sand, the mid summer mid day heat and thirst. In mid summer desert conditions, the British infantry were unable to move effectively to pursue the retreating columns the next day and alone, the Anzac Mounted Division was unable to attack and capture Von Kressensteins large force which made an orderly retreat to Katia and eventually back to their base at Bir el Abd. Bir el Abd was abandoned on 12 August 1916 after fierce fighting, during an attack by the Anzac Mounted Division on 9 August, at the extremity of British Empire lines of communication. This was the first substantial Allied victory against the Ottoman Empire in World War I, ending the Defence of the Suez Canal campaign. The Canal was never again threatened by land forces during the remainder of the war. The Allies then went on the offensive for seven months, pushing the Ottoman Army back across the Sinai Peninsula, fighting the Battles of Magdhaba and 