In 1540, he travelled abroad with his cousin and visited Constantinople, Venice, Milan and Vienna, where his cousin died. He served in the war against France on land and at sea. In 1544, he led a company of foot apparelled in black at his own expense, with his brother George Carew – who was in command of the "Mary Rose" when she sank – and served as commander of the horse. For his service in the campaign he was knighted in 1545.