Boyle Roche entered the army at an early age, and served in the so-called American war (that is, the American portion of the Seven Years' War). There are reports of a Lieutenant Boyle Roche in Rogers' Rangers who was captured by the French during The Battle on Snowshoes (near what is now Lake George, New York in March 1758) and later returned to his regiment. It is possible that Roche served with Wolfe at the in 1759; it is a certainty that he distinguished himself in 1762 during the capture of El Morro in Havana. By 1770 he had become a major in the 28th Foot. He was knighted for his bravery at El Morro in 1776.