Mary was apparently ill and weak starting around May 1558. It is believed that she may have been suffering from ovarian cysts or a form of uterine cancer, and contemporary reports reveal that she was in a great deal of pain during her final months. Her death has been a bit ambiguous, because there was an influenza epidemic at the time, so it is sometimes said that she died from influenza. Other reports include various cancers, including stomach cancer. Although we don't know for sure what the ultimate cause of her death was, it is safe to say that she suffered quite a lot from May to November.
Mary received the last rites in her chamber at St. James Palace just before midnight on 16 November. She died a few hours later, between five and six in the morning. During her final week or so, she had ordered that mass be celebrated in her chambers for her to see, and as dawn broke on the day of her death, she reportedly passed away while watching the elevation of the host. According to a later account, she had "comforted those of them that grieved about her, she told them what good dreams she had, seeing many little children, like Angels playing before her, singing pleasing notes."
Although the queen's death certainly caused mourning among her supporters and friends, it marked the dawn of a new age and a happier reign with Elizabeth Tudor. Bonfires were lit across England and the nation was generally excited and looking forward to the new queen's coronation. The bloody days of Mary Tudor were behind them, and the Golden Age was about to arrive.
As you know, I'm a strong supporter of Mary Tudor, although I definitely don't condone everything she did. She was a woman with many problems in her life, a deficit of love around her, and policies that made her incredibly unpopular. Hers was not an easy life, and it was a depressing and lonely death. Take a few minutes today to think of the queen who is too often plagued with cruel names and thought to be a monster. Consider her struggles and her life as a whole, and offer up the sympathy that she undoubtedly deserves.
Rest in Peace, Queen Mary I!