What title was held by the man who was thought to have died at the Battle of Stamford Bridge, who also spent 15 years in exile?
Harald Hardrada Harald Sigurdsson (Old Norse: "Haraldr Sigurðarson" ;  1015 – 25 September 1066), given the epithet Hardråde ("harðráði ", roughly translated as "stern counsel" or "hard ruler") in the sagas, was King of Norway (as Harald III) from 1046 to 1066. In addition, he unsuccessfully claimed the Danish throne until 1064 and the English throne in 1066. Prior to becoming king, Harald had spent around fifteen years in exile as a mercenary and military commander in Kievan Rus' and of the Varangian Guard in the Byzantine Empire.
Murdoch Stewart, Duke of Albany Murdoch Stewart, Duke of Albany (Scottish Gaelic: "Muireadhach Stiubhart" ) (1362 – 24 May 1425) was a leading Scottish nobleman, the son of Robert Stewart, Duke of Albany and the grandson of King Robert II of Scotland, who founded the Stewart dynasty. In 1389, he became Justiciar North of the Forth. In 1402, he was captured at the Battle of Homildon Hill and would spend 12 years in captivity in England. After his father died in 1420, and while the future King James I of Scotland was himself held captive in England, Stewart served as Governor of Scotland until 1424, when James was finally ransomed and returned to Scotland. However, in 1425, soon after James's coronation, Stewart was arrested, found guilty of treason, and executed, along with two of his sons. His only surviving heir was James the Fat, who escaped to Antrim, Ireland, where he died in 1429. Stewart's wife Isabella of Lennox survived the destruction of her family, and she would live to see the murder of James I and the restoration of her title and estates.