Hamilton prepared his four divisions for the assault, only one of which, the 29th was a regular formation. The landings took place on the 25 April 1915 with the Turks, under the command of Liman von Sanders, a German, being deceived with feint assaults by the Royal Naval Division at Bulair and the French at Besika Bay. The landings showed imagination however and may well have succeeded early on, but for a combination of mediocre leadership, the shortage of time for preparation, the geography and terrain in the peninsula with its few beaches and constraints on logistic support. Unfortunately, the "British Army was too rigidly structured . . . to attempt amphibious operations" and it was "the antiquated command structure that impeded progress." (Travers, 1994, p. 223) The British advance crucially lost momentum, and the Australian and New Zealand Army Corps (ANZAC) landing on the western coast between Gaba Tepe and Ari Burnu ('Anzac Cove') met with stiff resistance from the Turkish 2nd Division commanded by Colonel Mustapha Kemal (Atatürk) and almost got thrown back into the sea.
Between May and July, the French and British slowly advanced up the peninsula while the Anzacs clung to their small perimeter, inflicting massive losses on sustained Turkish attacks.
In August, a change of heart in London brought Hamilton reinforcements with which he prepared another ambitious offensive. The assault would be conducted in three parts. The first involved two columns from Anzac Cove (after it was reinforced with some 20,000 British and Gurkha troops) making their way through a relatively undefended route (reconnoitred by a New Zealander, Overton) to attack the key position (Chunuk Bair) in the Sari Bair mountains. The second involved the 1st Australian Division attacking the supposedly impregnable Lone Pine position and the third would be the amphibious operation with IX Corps, under General Stopford, at Suvla Bay, on the night of the 6 - 7 August. The Australian assault on Lone Pine succeeded due to careful and imaginative planning. The two columns came very close to succeeding in their missions but the right column suffered delays due to exhaustion and so missed the opportunity to initially take Chunuk Bair but managed to take it with the help of the remainder of the left column, who, after being badly mauled by artillery fire, failed to take Hill Q. They were subsequently thrown off Chunuk Bair by a near suicidal charge led by Kemel. The great gamble had failed. The landings at Suvla were conducted successfully, but the British forces were slow to exploit this and after they had finally started moving, attacked the Turkish forces defending the Suvla Plain on the 21 August from which they could not be dislodged.
Hamilton was recalled and his replacement Monro, advised evacuation, which was eventually agreed. Churchill resigned and went to the Western Front. The evacuations were organised and conducted in a real show of brilliance, first of Anzac-Suvla and then of Helles in December and January, with not a man being lost, under the noses of the Germans and Turks who had nothing but admiration for their conduct. The campaign had cost the Allies some 46,000 killed (26,000 British) and the Turks, over 200,000. One cannot help but wonder about what might-have-been, with the narrowness between victory and defeat being an extremely slim one.