Brock, in 1805, was made full colonel. After the incident of the mutiny he had taken over the active command at Fort George as well as at York, and at the former, as at the latter, a new and kindlier order of discipline was worked out. In this, Lieutenant-Colonel Sheaffe seems to have helped. No doubt he was influenced by reflecting on the trouble he had helped to cause. Later on, in reporting the excellent discipline of the 49th, Brock gave a good deal of the credit to Sheaffe. Desertions were in bad odor, for the commanding officer gave his men no reason for leaving him.

In October Brock went to England on leave. While he was glad to see his old friends again, he made business his first consideration and discussed with the British commander-in-chief, the Duke of York, the military situation in the Canadas. He proposed the establishment of veteran battalions. He instanced the attractiveness of desertion to the soldier quartered near the United States border and pointed out that the immigration from the United States to Canada of undesirable settlers—undesirable since they owed no allegiance to the British flag—might possibly counterbalance the devotion of the United Empire Loyalists. He suggested that these veterans should serve a certain time and that they should then be given an opportunity to settle on the land. The Duke warmly thanked Brock, and later on the plan was adopted.

Brock turned his steps Guernsey-wards, but after a few days there news of real trouble with the United States made it imperative that he should return to his command. Shortening his leave, he set sail on June 26th, 1806, and never returned to England.

When he arrived in Quebec he found himself the senior officer of military rank in the Canadas and, as such, at once assumed the command of all the forces.

The war cloud was gathering. Although Nelson’s victory at Trafalgar had finally shattered Napoleon’s dream of invading England, he still hoped to cripple her by destroying her commerce and cutting off her food supply. Rapidly he subjugated Austria and Prussia, and when these two countries were at his feet, from the capital of Prussia he issued the famous Berlin Decree. This decree forbade France or any of her allies to trade with Britain and declared that any ship engaged in such trade might be lawfully seized as a prize of war. Britain did not meekly submit, but by various orders in council forbade the ships of any nation to trade with France or any of her allies. Both the Berlin Decree and the orders in council were very high handed proceedings and bore with special severity on the neutral nations.

At this time the relations between the United States and Great Britain were very strained. In order to maintain her navy at its full strength, Britain had revived her ancient “right of search.” She claimed and exercised the right to search the ships of neutral nations to find if they were carrying British subjects who were deserters from the British navy. The United States protested strongly against this action of Great Britain, holding that once a British seaman had crossed the decks of an American ship he was an American, and, moreover, she declined to acknowledge any right of Great Britain to hold up and to search her ships on the chance of finding deserters. And now came the British orders in council as a further source of irritation.

It is true that the commerce of the United States with foreign nations had practically ceased as a result of the actions of the warring powers in Europe, but for this the Berlin Decrees were as much to blame as the orders in council. In fact at this time the United States suffered innumerable humiliations at the hands of the French. But in spite of this the whole anger of the United States seemed to be directed against Great Britain. The bitterness produced by the Revolutionary War had not yet died down, and there was a strong party in the country who made it its business to increase the flame of hatred. This party looked with covetous eyes on Canada, and desired to incorporate it into the United States. Without question that was the underlying reason for the War of 1812-14.

President Jefferson was a bitter enemy of Great Britain. While Brock was still in England, the president addressed Congress and said that “the impressment of American seamen by British cruisers, not at all checked by the remonstrances of the American Government, was a growing source of irritation and complaint.... She [Britain] plainly showed a disposition to narrow the limits of the commerce of neutrals by denying to them the right of carrying on a trade with belligerents which she did not interdict with her own subjects.” Britain’s view was that as she was trying to beat the man who was doing his best to conquer Europe, the United States should see that if extreme measures were necessary they must be borne with, even though they hurt for the moment.

At the end of 1805 President Jefferson went further. He came out flatly and said that “the foreign relations of the United States had been materially changed since the preceding session.” He charged Britain with piracy and infesting the American coast with private armed vessels, “which had perpetrated acts beyond their commission.” And he said: “It is due to ourselves to provide effective opposition to a doctrine which is as infamous as it is unwarranted.”

Brock recognized the veiled threat in the words “effective opposition” and was convinced that Jefferson and that section of the United States for which he stood wanted war. Hence his quick return to Canada. He knew that Jefferson’s first act in the event of war would be to try and get control of the lakes and rivers and to capture the fortified posts. Brock realized better than any man how weak was the resistance that could be offered unless the defences of the Canadas were immediately strengthened. As soon as he had taken up his new command he set about preparing the defence Canada was to offer. In this he was hampered rather than helped by the civil authorities. The governor-general of the Canadas at this time, Sir Robert Prescott, does not seem to have taken his position very seriously, and Thomas Dunn, president of the Executive Council, the man with whom Brock had directly to deal, appears to have been of one mind with Prescott.