 Lacking special political connections, Brock's ability to gain promotions even when the nation was at peace attests to his skills in recruiting men and organizing finances, and ambition.At the age of fifteen, Brock joined the 8th (The King's) Regiment of Foot on 8 March 1785 with the rank of ensign, and was likely given responsibility for the regimental colours.His elder brother John was already an officer in the same regiment.