Book excerpt: An illustrated history of the American-built destroyers and frigates supplied to the Royal Navy under Lend-Lease, which played a crucial role in Britain's war in the Atlantic. As U-boat attacks on Britain's vital sea lanes increased in ferocity, and Royal Navy warship losses mounted, the United States passed the Lend-Lease Act, the cornerstone of America's wartime role as armourer to the Allies. Naval historian Angus Konstam here offers an account of the Royal Navy's Lend-Lease destroyers and escorts. The first batch were 50 World War I-era 'four-stacker' destroyers, in a deal sealed by the transfer of several global British bases to the USA. These warships were immediately recrewed, refitted and pressed into service in the Battle of the Atlantic. These ageing destroyers were followed by over a hundred more Lend-Lease warships, many of which were built especially for British service in American shipyards. Their arrival helped tip the balance in the hard-fought war against the U-boats, while others were used to fulfil other crucial wartime missions. With detailed ship profiles of the major classes, a cutaway of HMS Campbeltown (of Saint-Nazaire raid fame) as it appeared in 1941, and superb battlescene artwork, this is a comprehensive look at a crucial aspect of the Battle of the Atlantic.