In late 1810, at the height of his popularity, already virtually blind with cataracts and in pain from rheumatism, George III became dangerously ill. In his view the malady had been triggered by stress over the death of his youngest and favourite daughter, Princess Amelia. The Princess's nurse reported that "the scenes of distress and crying every day ... were melancholy beyond description." He accepted the need for the Regency Act 1811, and the Prince of Wales acted as Regent for the remainder of George III's life. Despite signs of a recovery in May 1811, by the end of the year George had become permanently insane and lived in seclusion at Windsor Castle until his death.