Under the 1670 Treaty of Dover, England agreed an alliance with France against the Dutch Republic, including the supply of 6,000 troops for the French army. It also contained secret provisions which were not revealed until 1771, including the payment to Charles of £230,000 per year for these troops. The Brigade fought primarily in the Rhineland, to avoid potential clashes with English and Scots serving with the Dutch; a large part of it was provided by Dumbarton, whose regiment was expanded to 33 companies or 3,432 men.