 On 5 May 1500 he witnessed at Canterbury the treaty for the marriage of Prince Arthur with Catherine of Aragon.He then left for France, arriving there on the 13th, and attended the King at his meeting with the Archduke Philip son of Emperor Maximilian I, at Calais, on 9 June 1500.In August 1501 he and his brother Richard again left England without Royal leave (apparently assisted by James Tyrrell, who was subsequently executed for these actions), and joining Emperor Maximilian I in the Tyrol, he assumed his former title of Duke of Suffolk, being also known as the "White Rose" (Yorkist Pretender).