The second son of Sir James Chatterton, 1st Baronet, and his wife Rebecca Lane, he joined the 12th Light Dragoons in 1809 and took part in the subsequent Peninsular War (1807–1814). He saw action at the sieges of Ciudad Rodrigo and Badajoz and the battles of Salamanca, Vittoria, Nivelle and the Nive as well as other minor actions. For his services in the Peninsular, Chatterton received the Army Gold Medal with seven clasps.