After nine grueling months of combat, ANZAC troops led the charge into the capital of the Ottoman Empire and brought about its surrender. It was a campaign that was conceived initially by First Lord of the Admiralty Winston Churchill and solved many of the Allies' problems after the opening of the World War had come to stalemate. Trench warfare in France had come to a standstill, and the Allies needed a new front to break into the territory of the Central Powers. First Sea Lord John Fisher suggested an amphibious landing in Germany itself to break the Kaiser's strength at home, but Churchill suggested taking the Dardanelles, which would break up the Ottoman Empire while also making use of outdated naval ships unfit for combat against the German fleet as well as establishing supply lines to Russia, which was effectively cut off from the rest of the Allies by the Central fronts, German ships, and ice.
Churchill won the debate, and an Allied fleet made its first attack on February 19, 1915. Initial bombardment weakened the fortresses along the Dardanelles, so Admiral Carden cabled Churchill that victory would be assured by a major push in early March. Fisher and others in the Navy noted that losses would be severe, and Fisher repeatedly threatened to resign over the matter. Churchill initially dismissed the notion, saying that war was war, but he finally conceded and asked Fisher to outline a battle plan with minimal loss. Instead of the direct attack planned, the navy would give support while covert agents swept for mines and destroyed mobile artillery that could attack from anywhere along the shore.
Rather than the direct attack, the British and French fleets moved slowly and methodically, eliminating any possible mines while the Ottomans continued to patrol and strike whenever possible. The latter struggled constantly with low ammunition, and the Allies gradually made their way upward to the forts guarding the narrow-most corridor of the Dardanelles. Under naval artillery support, troops were landed at Cape Helles, most notably the Australia and New Zealand Army Corps, who had been training in Egypt for battle in France and suddenly reassigned. Also among them were elite troops in the British Gurkhas, the Jewish Legion, and many English and Irish. The Ottomans fought back fiercely, such as the stand of the 57th Infantry Regiment under the command Lieutenant-Colonel Mustafa Kemal, who said, “I do not expect you to attack, I order you to die. In the time which passes until we die, other troops and commanders can come forward and take our places.”
Over the course of the next months, battle after battle would press the Allies forward. Both armies would suffer from intense heat in the summer, mosquitoes and vermin, storms, flooding, and frostbite during the winter. That spring, the navy would break through the strait and gain open water in the Sea of Marmara, setting up a new stage for the campaign in besieging and assaulting Istanbul. Joined by the Russian fleet from across the Black Sea, the city would be cut off from the rest of the empire, which would shatter over the course of 1916. The Armenians, who had been executed en masse for their volunteer forces in Russia, rebelled openly and were promised their own nation-state. The Young Turk movement, which had been suppressed and even turned to fight against the invasion of the Allies, now declared the caliphate abolished, establishing a new republic. Other territories of the Ottomans were broken apart, though diplomats were busy solidifying the entrances of Romania and Greece into the war and left the divisions to the Arab Bureau of the Foreign Office, working primarily with archeologist / Intelligence Officer T.E. Lawrence and General Archibald Murray of the Egyptian Expeditionary Force. The new national lines followed the division of people groups, notoriously spawning wars in the Middle East throughout the twentieth century, though rarely violent internal matters.
The collapse of the Ottoman Empire seemed a great boon for the Allies, but the fall of Russia later that year would bring the war to another standstill until won after the entrance of the United States and devastating Spanish Flu pandemic. The signing of the Treaty of Versailles would be the first great note of Sir Winston Churchill's career as Prime Minister.
In reality, the Gallipoli Campaign would be one of the bloodiest failures of the Allies in World War I, ending with an evacuation of troops on January 9, 1916. Churchill and Fisher would argue to the point of Fisher's resignation, though the two retained mutual respect. Churchill received much of the blame for the failures at Gallipoli and was demoted, eventually taking a short retirement from politics and commanding an infantry battalion on the Western Front. The genocide against the Armenians, which would total over one million deaths, is believed to have been intensified because of the desperation of war in Gallipoli.