HMT Royal Edward RMS ( later HMT ) Royal Edward was a passenger ship belonging to the Canadian Northern Steamship Company that was sunk during the First World War with a large loss of life while transporting Commonwealth troops . She was launched in 1907 as RMS " Cairo " for a British mail service to Egypt . Design and construction . " Cairo " and sister ship were built by the Fairfield Shipbuilding and Engineering Company of Govan , Scotland . " Cairo " was launched in July 1907 and entered service in January 1908 . As built , she was long ( overall ) and abeam . She was powered by three steam turbines that drove three propeller shafts , at up to . She could accommodate up to 1 , 114 passengers in three classes : 344 in first class , 210 in second class , and 560 in third . Prewar career . " Cairo " entered service for the Egyptian Mail Steamship Company , a British - owned company that provided a fast mail service between Marsailles and Alexandria . The service was not successful and " Cairo " and sister ship " Heliopolis " were laid up in 1909 when the service ended . Both ships were sold to the newly established Toronto - based Canadian Northern Steamship Company , a subsidiary of the Canadian Northern Railway , in 1910 , operating under its Royal Line brand . " Cairo " was renamed " Royal Edward " , " Heliopolis " " Royal George " , and they were refitted for the North Atlantic . " Royal Edward " sailed from Avonmouth to Montreal in the summer and to Halifax in the winter . At the outbreak of World War I " Royal Edward " and " Royal George " were requisitioned for use as troopships . World War I . On 28 July 1915 , " Royal Edward " embarked 1 , 367 officers and men at Avonmouth . The majority were reinforcements for the British 29th Infantry , with members of the Royal Army Medical Corps . All were destined for Gallipoli . " Royal Edward " was reported off the Lizard on the evening of the 28th , and had arrived at Alexandria on 10 August , a day after sister ship " Royal George " had sailed from Devonport . " Royal Edward " sailed for Moudros on the island of Lemnos , a staging point for the Dardanelles . On the morning of 13 August , " Royal Edward " passed the British hospital ship , heading in the opposite direction . " Oberleutnant zur See " Heino von Heimburg in the German submarine was off the island of Kandeloussa and saw both ships . He allowed " Soudan " to pass unmolested , and focused his attention on the unescorted " Royal Edward " some off Kandeloussa . He launched one of " UB - 14 " s two torpedoes from about a mile ( 2 km ) away and hit " Royal Edward " in the stern . She sank by the stern within six minutes . " Royal Edward " was able to get off an SOS before losing power , and " Soudan " arrived on the scene at 10 : 00 after making a 180° turn and rescued 440 men in six hours . Two French destroyer s and some trawlers rescued another 221 . According to authors James Wise and Scott Baron , " Royal Edward " s death toll was 935 and was high because " Royal Edward " had just completed a boat drill and the majority of the men were below decks re - stowing their equipment . Other sources report different numbers of casualties , from 132 to 1 , 386 or 1 , 865 . Notes . HMT does not stand for His / Her Majesty ' s Troopship . This error is commonplace . It actually stands for Hired Military Transport .