The Anzacs managed to dig themselves in at Kabatepe in the days following the landing on the Gallipoli peninsula in April 1915. They were exhausted, and hemmed in to a very small area.
An attempt to drive the Turkish defenders back at a hill the Anzacs dubbed Baby 700 failed, and the Otago Battalion suffered heavy casualties. The troops, now including the New Zealand Mounted Rifle Brigade - minus their horses - brought forward from Egypt, awaited the assault from the Turks. This came on 19 May.
More than 40,000 Turks threw themselves at the Anzac lines, determined to drive the invaders into the sea. By the time the attacks petered out, some 10,000 had become casualties.
A truce five days later allowed many of the corpses, both Turkish and Anzac, in no man's land to be buried in shallow graves. In the aftermath of this attack, the two sides continued to fight vicious little battles, but the Anzac line held.
In the northern sector there was no continuous front line, but a series of connected outposts. The Australian Division took responsibility for the line from Courtney's Post southwards.
The New Zealand and Australian Division held Quinn's Post and the positions facing north. Quinn's Post was supported by troops on Pope's Hill, a spur at the head of Monash Valley, and Russell's Top, higher ground at the top of Walker's Ridge.
The trenches on Russell's Top were separated from the Turks on Baby 700 by a narrow saddle, which became known as The Nek. Trenches on Walker's Ridge guarded the Anzac northern flank on the seaward side of the Sari Bair range.
To prevent the Turks moving down the valleys from the range and attacking Anzac from the north, a series of outposts - Chailak Dere and Sazli Beit Dere - were established at the mouths of the valleys.