British ships blockading the Dardanelles bombard the Turkish forts guarding the entrance to the Straits.The naval operations in the Dardanelles Campaign of the First World War were mainly carried out by the Royal Navy with substantial support from the French and minor contributions from Russia and Australia. The Dardanelles Campaign began as a purely naval operation. When that failed to overcome Ottoman defences, an invasion of the Gallipoli peninsula was launched in which naval forces were heavily involved. Throughout the campaign, attempts were made by submarines to pass through the Dardanelles and disrupt Ottoma Empire shipping in the Sea of Marmara.