Orkney from mainland Scotland sought refuge on Orkney and were helped on to safety in Sweden. In 1745, the Jacobite lairds on the islands ensured that Orkney remained pro-Jacobite in outlook, and was a safe place to land supplies from Spain to aid their cause. Orkney was the last place in the British Isles that held out for the Jacobites and was not retaken by the British Government until 24 May 1746, over a month after the defeat of the main Jacobite army at Culloden. Orkney was the site of a Royal Navy base at Scapa Flow, which played a major
Naval warfare of World War I of mines, occasionally attempting to lure the British fleet into battle (one of such attempts was the bombardment of Yarmouth and Lowestoft) in the hopes of weakening them enough to break the blockade or allow the High Seas Fleet to attack British shipping and trade. Britain strove to maintain the blockade and, if possible, to damage the German fleet enough to remove the threat to the islands and free the Grand Fleet for use elsewhere. In 1918 the U.S. Navy with British help laid the North Sea Mine Barrage designed to keep u-boats from slipping into the Atlantic. Major battles