After this king's brother married the commoner Ann
After this king's brother married the commoner Anne Horton, Parliament gave him veto power over royal marriages with the Royal Marriages Act. Issue 45 of the North Briton mocked a speech made by this man, leading to the imprisonment of John Wilkes. This recipient of the Olive Branch Petition ordered William Howe to put down a colonial rebellion. This man's son of the same name served as regent after this king's urine became blue from porphyria. For 10 points, name this mad Hanoverian monarch who lost the American colonies.
After this king's brother married the commoner Anne Horton, Parliament gave him veto power over royal marriages with the Royal Marriages Act.
George III [or George William Frederick III; prompt on "George;" prompt on "George Hanover"]