Arthur's wife, Catherine.
Prince Arthur Tudor of Wales was the son of Henry VII and Elizabeth of York. He was the first in line to the throne and represented the physical union of the house of York and of Lancaster. He married Catherine of Aragon in 1501; when he was only fifteen years old.
In the spring of 1502, Arthur and Catherine were taken ill with a well-known malady of the time, "sweating sickness". Catherine recovered from the illness; but Arthur died of it on April 2, 1502 after a mere five months of marriage.
Season One[]
Henry feels that; he has no heir because it took his brother, Arthur's wife. By episode 1.07, Cardinal Wolsey sends agents to the exiled Pope asking him to make a favourable decision on Henry's "Great Matter"; but Clement instead sends his legate, legate Cardinal Campeggio, to; make a final decision in England.
In episode 1.08, Cardinal Campeggio arrives to hear the case for the annulment of Henry's marriage to Catherine of Aragon. Catherine plead their cases. Telling all that; she never did consummate the marriage; with Arthur.
Season Two[]
In episode 2.03, the clergy in England have mostly submitted to Henry. The new Archbishop of Canterbury, Thomas Cranmer declares Henry's marriage to Catherine null and void. To bring an end to his "Great Matter". Due to Arthur and Catherine's short marriage.