The naval operations in the Dardanelles campaign took place against the Ottoman Empire during the First World War. Ships of the Royal Navy, French Marine nationale, Imperial Russian Navy and the Royal Australian Navy, attempted to force a passage through the Dardanelles Straits, a narrow, 41 mi-long waterway connecting the Mediterranean Sea with the Sea of Marmara and the Black Sea further north.
The Ottoman defence and in particular their naval mines defeated the naval operation. The Allies conducted an invasion of the Gallipoli peninsula to clear the area of Ottoman artillery for a resumption of the naval operations. The Allies also tried to pass submarines through the Dardanelles to attack Ottoman shipping in the Sea of Marmara.