On 14th August 1914 sailed from Cape Town with mail and government only passengers to Gibraltar where she embarked troops before being escorted to England by HMS Minerva.
She was then taken over as an auxiliary cruiser for the South Atlantic patrol and in January 1915 sailed from Devonport for South Africa with White Star's Ceramic to hunt for the German ships Karlsruhe and Kronprins Wilhelm.
In 1918 served in the North Atlantic on convoy work. She resumed commercial operations in 1919 after a refit and during that year carried General Smuts back to South Africa.
She was withdrawn from service in 1938 and laid up at Netley until she was bought by the Admiralty for use as an accommodation ship in Freetown, Sierra Leone for Naval personnel and survivors of sunken ships.
In 1945, as towing back to England would not be cost effective, she was towed 60 miles out to sea by the tug Empire Lawn and sunk by gunfire and depth charges from the armed trawler Cape Warwick, HMS Porchester Castle and HMS Launceston Castle.
HMS Edinburgh Castle being towed out of Freetown Harbour by HMS Launceston Castle and the tug Empire Lawn.
The former Naval Depot Ship, HMS Edinburgh Castle being towed out of Freetown Harbour on her way to being sunk off the coast of Sierra Leone. The cost of towing her back to Britain was too great.
HMS Edinburgh Castle heels over to starboard and sinks in 45 fathoms of water after receiving her final death blow from the corvette HMS Porchester castle.