The Gallipoli campaign was an attempt by the Entente to secure the Turkish straits, allowing Russia to pass through, unimpeded. The Turkish straits are divided into 3 distinct sections: The Bosphorus, which divided the Ottoman capital city of Constantinople into 2, the sea of Marmara and finally another narrow section known as the Dardanelles. One side of this narrow section is the Gallipoli peninsula, where, following a series of unsuccessful naval battles against the Ottomans, the decision was made to conduct amphibious landings on the 25th of April 1915. The plan was to capture the Gallipoli peninsula and move up to Constantinople, but after 8 months of warfare the Entente was forced to abandon the endeavour.