On 20 June 1837, Victoria became Queen of the United Kingdom on the death of her uncle, William IV, just weeks after reaching the age of eighteen. Her government was led by the Whig prime minister Lord Melbourne, to whom she was close. But within two years he had resigned, and the Tory politician Sir Robert Peel attempted to form a new ministry. Peel said he was willing to become prime minister provided the Queen replaced her Whig ladies-in-waiting with Tory ones. She refused and re-appointed Lord Melbourne, a decision criticised as unconstitutional. She regularly recorded the events of the rebellions on Upper and Lower Canada as these reminded her of the American Revolution, which took place during the reign of her grandfather King George III. London sent Lord Durham to resolve the issue and his 1839 report opened the way for "responsible government" (that is, self-government).