I [Reginald Pole] will tell you of the grievous trouble and remorse which [...] the most Serene Queen Katharine [of Aragon], had to endure, as frequently alluded to by herself, always thinking of this, namely, that a great part of her troubles emanated from God, not through any fault of her own, but for the salvation of her soul; and that the Divine justice thus punished the sin of her father King Ferdinand, for when he commenced negotiating her marriage with Prince Arthur, the eldest son of the King of England [Henry VII], some disturbances took place at the time, owing to the favour and goodwill borne by the people to my mother's brother [Edward] the Earl of Warwick, [...] who being the son of [George] the Duke of Clarence, brother of King Edward [IV], became, by the death of that King's sons, next heir to the English crown. King Ferdinand [...] made a difficulty about it, saying he would not give her to one who was not secure in his own kingdom; and thus, by inciting the King to do what he already desired spontaneously, he was the cause of the death of that innocent Earl, who had no more blame in those commotions, nor could anything else be laid to his charge, save the danger which the King in Council alleged had already befallen him in part, through the existence of the said Earl; and in addition to this having heard the opinion of the King of Spain, he did that deed, of winch [...] he so greatly repented on his death-bed.
But the Divine justice did not permit so iniquitous an act of injustice to remain unpunished, for at the end of six months Prince Arthur died, nor could he any longer enjoy the wife who had been given him by such bad counsel [... ] To these causes that good Princess said that she attributed in great part the annoyances and distresses endured by her, confessing that she was therefore very much bound to recompense and requite us [the family of the Earl of Warwick] for the detriment we had received on her account (although she was not in the least to blame for it), and to show us every kindness, having found by experience that in all her sorrows and afflictions, from no family of the realm had she ever received greater consolation than from ours, although for her sake we had received so many injuries.
On Katharine of Aragon's belief that she was being divinely punished because of the execution of Edward, Earl of Warwick, and her resulting favour towards the Earl's family — including Margaret Pole, Countess of Salisbury and Cardinal Reginald Pole.
Excerpt from a letter to Cardinal Reginald Pole to Edward Seymour, Lord Protector of England, 7th September 1549.
From Calendar of State Papers Relating To English Affairs in the Archives of Venice, Volume 5, 1534-1554, edited by Rawdon Brown, published 1873.