Book excerpt: As the third and largest sister of the famous Olympic-class trio, Britannic is often and unjustly overlooked in comparison to Olympic and Titanic. Launched on the eve of war in February 1914, Britannic would never see service on the White Star Line's express service on the North Atlantic mail run for which she was built. After being requisitioned by the Admiralty in November 1915 His Majesty's Hospital Ship Britannic instead became indispensible to the thousands of injured and sick troops that needed transporting back to Britain from the Mediterranean theatre of war. However, as was the fate of many liners during the conflict, her life was cut tragically short when she was suddenly wracked by a mysterious explosion on 21 November 1916 and sank in less than an hour - three times faster than her sister ship Titanic, and yet thanks to the improvements in safety heralded by the tragedy of her sister 1,032 of 1,062 on board survived.Here Simon Mills brings together previously unseen material, including stunning colour images of Britannic's wreck in the Aegean Sea, and this poignant story to tell a tale of heroism in the First World War, of an oftoverlooked but key ship to British maritime history and of the unique future that the wreck might still one day enjoy.