A deep-rooted desire to believe that public figures who have died in mysterious circumstances somehow managed to escape their fate and survive for years thereafter seems to be as old as history. In 1113 a party of canons of Laon visiting Bodmin in Cornwall narrowly escaped being lynched by local inhabitants when they expressed mild scepticism at the belief that King Arthur had survived the Battle of Camlan in 542 and was living yet. After the Battle of Hastings biographies were compiled as far away as Iceland, asserting that Harold had escaped the slaughter to live on in caves and islands, or even as a hermit in Canterbury Cathedral, where he could spy on William the Conqueror at prayer. When Frederick Barbarossa was drowned on crusade, it was supposed for centuries that he dwelt on in splendour inside the Kyffhäuser Mountain in Thuringia. King Sebastian of Portugal, slain in 1578 at the battle of Alcazar-el-Kebir in Morocco, was believed as late as the nineteenth century to have survived and be living somewhere.

The massacre of the Russian Imperial Family in 1918 at Ekaterinburg horrified the world. It is often forgotten that this was the first widely known indiscriminate slaughter of innocents, which heralded the unprecedented terror that lasted until Stalin’s death thirty-five years later. Even Lenin realised that, while he might seek