With British entry in World War I, many available liners were requisitioned for use by the government: ''Olympic'' and ''Britannic'', once sisters to the ill-fated [[RMS Titanic|''Titanic'']], were taken from rival White Star Line and used as a troop transport and hospital ship, respectively. ''Mauritania'' as well as Cunard's third entry, ''Aquitania'', were also taken and used. ''Lusitania'' remained under Cunard control, as passenger service was still expected and needed; a possible clandestine use as a deliverer of military arms was not overlooked. | With British entry in World War I, many available liners were requisitioned for use by the government: ''Olympic'' and ''Britannic'', once sisters to the ill-fated [[RMS Titanic|''Titanic'']], were taken from rival White Star Line and used as a troop transport and hospital ship, respectively. ''Mauritania'' as well as Cunard's third entry, ''Aquitania'', were also taken and used. ''Lusitania'' remained under Cunard control, as passenger service was still expected and needed; a possible clandestine use as a deliverer of military arms was not overlooked. |