Ships of the Royal Navy, French Marine nationale, Imperial Russian Navy (Российский императорский флот) and the Royal Australian Navy, attempted to force the defences of the Dardanelles Straits. The straits are a narrow waterway connecting the Mediterranean Sea with the Black Sea, via the Aegean, Sea of Marmara and the Bosphorus. The Dardanelles campaign began as a naval operation but the success of the Ottoman defence led to the Gallipoli campaign, an attempt to occupy the Gallipoli peninsula with land forces supported by the navies, to open the sea route to Constantinople.