After his return to England in March, 1837, Colonel Arthur received the Hanoverian Order of Knighthood. At the close of the same year he was appointed Lieutenant-Governor of Upper Canada and at the same time given "the military rank and command of a major-general on the staff." Sir George Arthur was now nearly sixty years of age and had been for over twenty-two years a colonial governor. During that period he had wielded almost despotic power. It was not at all likely that he would be inclined to look with favour upon the demands of the Upper Canadian Reformers for "Responsible Government." On his arrival in Upper Canada Sir George Arthur was faced by a situation of the utmost delicacy. The rashness and wrong-headedness of Sir Francis Bond Head and of William Lyon MacKenzie had brought on the Upper Canadian Rebellion. The skirmish at Montgomery's Tavern occurred on Thursday, December 7th, 1837, and at the close of the day W. L. MacKenzie was a fugitive with a price on his head. The affair of the "Caroline" took place on December 29th. The destruction of this American steamboat resulted in considerable excitement in the United States and relations between the British and American governments became somewhat strained. The arrest and trial of Alexander McLeod on the charge of murdering Amos Durfee, an American citizen, who was killed during the raid on the "Caroline", further complicated the situation. It was not until 1842 that the incident was finally closed by a letter of apology addressed by Sir Robert Peel to Daniel Webster. Shortly after the destruction of the "Caroline" by the Canadians, MacKenzie's sympathizers, who had seized Navy Island in the Niagara River near the Falls, were forced to abandon their post, and the centre of disturbance shifted westward to the Detroit River. On this frontier an attack was planned by American sympathizers and disaffected Canadians against Fort Madden which was situated sixteen miles from Windsor, Ontario. The attempt proved disastrous and resulted in the capture of "General" Theller and other American sympathizers, who were sent to Toronto for trial. On the 3rd of March, 1838, Pelee Island in Lake Erie was captured by another band of invaders who were driven off by a Canadian loyalist force under Colonel Maitland. This was the last serious attempt made from the United States before the arrival in Upper Canada of Sir George Arthur.