He was the third and youngest son of Thomas Bradford, of Woodlands, near Doncaster and Ashdown Park, Sussex and Elizabeth, daughter of William Otter, of Welham, Nottinghamshire. Originally an ensign in the 1st West York Militia, he was gazetted as ensign without purchase in the 4th Foot on 6November 1801. He purchased a lieutenancy in January 1801. Appointed "aide-de-camp" to the Earl of Chatham, he saw service in the Peninsular War at the battles of Corunna, Salamance, Vittoria, The Pyrenees, Nivelle, Orthes and Toulouse.