I understand that to be true. And as a reason I seem to recall reading that Catherine was of the royal Spanish blood line and the Spanish Army had taken over for the Swiss Guards during this time frame. I may be off on this, as it has been many years.
Catherine of Aragon was the aunt of Charles V, King of Spain and Holy Roman Emperor. Prior to Henry VIII’s application, Charles V had captured Rome and effectively imprisoned Pope Clement VII (such respect for the Vicar of Christ and Prince of Apostles!). The Pope could therefore do nothing without the approval of Charles V.
The succession of Mary Tudor would mean Charles V’s own first cousin would rule England. If her succession were challenged internally (which is what happened to Matilda, who was the last princess to attempt succession), Charles V could internvene militarily. He would prop Mary up on the throne and even induce her to marry a Spanish prince, thus turning England over to the ruling family of Spain. That is why the succession of Mary had to be prevented at all costs.
The Pope actually didn’t deny Henry’s application. He refused to act upon it, and the case dragged out for years. At one point the Pope floated the idea that perhaps Henry could be allowed to commit polygamy to solve the problem. It came to the point that England could wait no more, and so the Archbishop of Canterbury decided the case and issued the annulment. Parliament passed the Act of Restraint in Appeals to end the Pope’s appellate jurisdiction over all legal matters in England- thereby preventing Catherine from appealing the annulment to Rome.