Margaret of York took a leading role in the Yorkist Templar plot to overthrow King Henry VII. The Templars manipulated the young Lambert Simnel into pretending to the Earl of Warwick, and later assigned Perkin Warbeck to pretend to be Richard of Shrewsbury, 1st Duke of York, both individuals with claims to the throne. Henry VII thwarted each attempt, imprisoning Simnel and hanging Warbeck.