High King selection over other kings ensured there would always be an adult on the throne, but warfare and murder followed. Overlordship was only submission under duress, ignored unless enforced. Vikings kept coming, to settle, fight for possession, or for hire. Highland Chiefs are re-aligned by sourced history. Sigurd Rollo raided Scotland and became Jarl of Shetland and Orkney. He landed on the northern coast of France where his descendants became Dukes of Normandy. Erik Rollo accompanied his uncle, William the Conqueror, on the invasion of England, and Richard, followed King David I of Scotland when he left the English court to reclaim his Scottish throne. Wallace was betrayed. 'Rollo' first appears in a 1141 charter granted by Robert de Brus, another Norman Viking descendant. Sir Henry de Bohun, an English knight, was killed by Robert the Bruce before his Battle of Bannockburn.