Sir William Stanley (d. 1495): Younger brother of Thomas, Lord Stanley, later Earl of Derby. With his brother, he carefully played both sides during the Wars of the Roses. But at the Battle of Bosworth in 1485, it was Sir William's forces who came to the rescue of Henry Tudor, killing Richard III and allowing Henry to usurp the throne as Henry VII. Sir William's brother Thomas, who was married to Henry's mother Margaret Beaufort, became Earl of Derby as a result -- but Henry VII executed William Stanley in 1495 as the result of an alleged conspiracy. What this says about the Stanleys, and about Henry, is left as an exercise for the reader.