 In 1502 , Arthur died at the age of 15 of sweating sickness , just 20 weeks after his marriage to Catherine . Arthur 's death thrust all his duties upon his younger brother , the 10 @-@ year @-@ old Henry . After a little debate , Henry became the new Duke of Cornwall in October 1502 , and the new Prince of Wales and Earl of Chester in February 1503 . Henry VII gave the boy few tasks . Young Henry was strictly supervised and did not appear in public . As a result , the young Henry would later ascend the throne " untrained in the exacting art of kingship . " 
