At the outbreak of the Second World War, Britain, desperately short of merchant shipping, turned to the Norwegians who agreed to loan several hundred of its modern cargo and tanker ships. In early 1940 when Hitler invaded Norway, both the British and Germans rushed to seize the remainder of the fleet. King Haakon VII and his government, now fleeing from Nazi occupation, refused to relinquish control of this vital national asset. Instead, they nationalized the fleet and established the Norwegian Shipping and Trade Mission. Nicknamed Nortraship, it became overnight the largest shipping company the world had seen with a thousand ships and offices on six continents. Generously made available to Great Britain, it became a priceless Allied asset without which victory over Germany would arguably have been impossible. By the end of the war, about half Nortraship's fleet had been lost to enemy action. The Saga of Norway's Merchant Fleet in the Second World War is a superbly researched addition to Second World War history being the first detailed account in English of Norway's critical contribution to the Allies. As well as telling this little-known but hugely significant story, the author covers the controversies that developed and persist into the present day.