The Nek was a vitally important position on the northern end of the ANZAC front line and the scene of a tragic attack by the 3rd Light Horse Brigade at dawn on 7 August 1915. It was a narrow bridge of land that stretched between Russell's Top and Baby 700 across the top of Monash Valley. The Turkish trenches on the slopes of Baby 700 allowed them to dominate the Australian positions below.
As part of the diversionary effort for the August Offensive, the 3rd Light Horse was ordered to attack the Turkish trenches at the Nek at 4.30am on 7 August to support an attack on Baby 700 by New Zealand troops who were to have captured Chunuk Bair the previous evening. The attack commenced with a bombardment of the Turkish positions by a destroyer steaming offshore, but the bulk of the shells fell beyond their target and the bombardment ended seven minutes early. Instead of charging at this point, the officers of the light horse held their men back until the appointed time for the attack arrived. This gave the Turks time to man their positions, having sought shelter during the bombardment.
The first wave of light horsemen from the 8th Light Horse Regiment were shot down by Turkish rifle and machine-gun fire. The second line, also from the 8th, scrambled over the dead and wounded of the first line to make their attack, and suffered the same fate. Cancellation of the attack was proposed, but was rejected by Major John Antill, who had taken over effective command of the 3rd Brigade. The third line of soldiers, from the 10th Light Horse, went over the top and were also shot down. Cancellation was again suggested, but before a decision was made, the right flank of the fourth line charged as a result of a misunderstanding, and the rest of the line followed. They too were mowed down by the Turkish fire. The 8th Light Horse suffered 234 casualties, 154 fatal; and the 10th, suffered 138 casualties, 80 fatal.