Nixon was a prophet who may have lived during the reign of Henry VII or James I - may have because no one's sure if he actually existed. His prophecies were recorded as early as the 1520s, and still being reissued as late as the 1790s in a Doomsday collection. They were interpreted by both the Jacobites and Hanoverians to their own advantage during one of the many battles over the British throne in the early 18th century.
According to surviving records (all written in later centuries, muddying the history), Nixon was simple-minded ploughboy brought to court because of his reputation for falling into trances and making prophecies. A 19th century account claims he "saw" the Battle of Bosworth Field while ploughing. One of his prophecies was that he would starve to death at Hampton Court, which happened when the cooks locked him in a cellar to punish him for being a nuisance, and then forgot about him when the court moved into London later that day.