The Dardanelles campaign, as conceived by Winston Churchill early in 1915, was primarily intended to relieve Russia of Turkish pressure in the Caucasus and also assist her by opening supply lines to the Black Sea. Secondarily, knocking Turkey out of the war might have encouraged Bulgaria and Greece to declare on the side of the Entente. Also, by this time the western front consisted of trench fortifications from the North Sea to the Alps and so another route at the Central Powers through the “soft underbelly of Europe” was desirable.
The initial plan was for a purely naval assault to force the Dardanelles, threaten Constantinople and force Turkey to her knees. Several attempts to penetrate the straits in by the British and French fleets failed. On March 18th the final attempt was defeated and three battleships were lost to mines. The decision to commit the army to an amphibious assault on the Gallipoli peninsula was made on March 22nd by General Hamilton and Admiral De Robeck.
The landings took place on April 25th, the British at Cape Hellas, The Australians and New Zealanders further north at what was to become known as ANZAC Cove and the French, as a diversion, on the Asiatic shore. The landings at Cape Hellas were soon in disarray; 6500 casualties and little more than a foothold ashore. Confusion also reigned at ANZAC Cove, where the assault troops had landed one mile north of the intended beach. Before any significant gains could be made they were held up by Turkish troops under Mustafa Kemal (The future President Ataturk). 2900 ANZACs were killed or wounded.
Despite multiple offensives by both Allies and Turks over the next three months the situation became a stalemate with the Allies still clinging to their enclaves on the tip of the peninsula. Hamilton decided on a fresh landing further north to drive a Corps of fresh troops across the neck of peninsula thereby cutting off the Turkish routes for supply and reinforcements.
The landings would take place on August 6th at Suvla Bay while diversionary assaults were put in at ANZAC and Hellas.
From Gallipoli, Alan Moorehead