HMS E14 sailed for the Mediterranean on 27 March 1915, in company with HMS E15, HMS E11 and the depot ship HMS ADAMANT, arriving at Mudros on 9 April. E14 conducted three war patrols in the Sea of Marmara between 27 April and 12 August 1915 (for which her commanding officer (then Lt Cdr Boyle) was awarded the Victoria Cross).

Later, in January 1918, under the command of Lt Cdr G S White, she was ordered to attack the German Goeben at Charnak. She successfully broke through the anti-submarine net at Charnak to find the Goeben had departed. She attacked a Turkish ship and shortly afterwards experienced a huge explosion that sprung the forward hatch, allowing water into the boat. She surfaced and suffered a fierce barrage of gunfire. White was the first onto the bridge and ordered the submarine to be steered towards the shore. His last words were: We are in the hands of God . Lt Cdr White, the father of two sons and an unborn daughter, remained on the bridge alone. He was killed by a shell while endeavouring to beach E14 and thereby save the lives of his ship company. In the event only seven crewmen were eventually rescued from the sea by the Turks and sent to prison camps. The Coxswain of the submarine managed to write a letter that, in time, reached England and the story of E14 fate became known. It wasn t until May 1919 that Lt Cdr White was awarded the Victoria Cross posthumously.