Henry VII was always worried about being overthrown by rivals for the thrown. Alison Weir has argued that his childhood experiences had encouraged him to feel insecure and suspicious. "He presented to the world a genial, smiling countenance, yet beneath it he was suspicious, devious and parsimonious. He had grown to manhood in an environment of treachery and intrigue, and as a result never knew security." (18)

In February 1487, Lambert Simnel had appeared in Ireland, claiming to be Edward, earl of Warwick, the young son of Edward IV's brother George, duke of Clarence. In February 1487 Lambert Simnel appeared in Dublin and claimed to be Edward, earl of Warwick, son and heir of George Plantagenet, Duke of Clarence, the brother of Edward IV, and the last surviving male of the House of York. (19) Polydore Vergil described him as as "a comely youth, and well favoured, not without some extraordinary dignity and grace of aspect". (20)

It is believed that John de la Pole, Earl of Lincoln, nephew of the Yorkist kings, was the leader of the conspiracy. He sailed to Ireland with over 1,500 German mercenaries. With this protection, Simnel was crowned as King Edward VI. Pole and his mercenaries, joined by 4,000 Irish troops, arrived on the Cumbrian coast on 4th June and marched across northern Lancashire before moving south. Henry's army, probably twice the size of Pole's, headed north from London. (21)

Henry was well-prepared, having positioned himself strategically to raise support, and advanced purposefully northwards from Leicester. "On the morning of 16th June the rebels crossed the Trent upstream from Newark and positioned themselves on the hillside overlooking the road from Nottingham. The battle of Stoke was a sharp and brutal encounter." (22) Henry's archers decimated the rebel army. The Earl of Lincoln was killed during the battle and Lambert Simnel was captured.

According to Polydore Vergil Henry VII spared Lambert Simnel, and put him to service, first in the scullery, and later as a falconer. (23) Jasper Ridley claims that this shows that "Henry VII... was not a vindictive man, and his style of government was quiet and efficient, never using more cruelty or deceit than was necessary. When he captured Lambert Simnel, the young tradesman's son who led the first revolt against him and was crowned King of England in Dublin, he did not put him to death, but employed him as a servant in his household." (24)