Armesto played Charles V, Holy Roman Empire in the series The Tudors.He starred in the 2008 ITV drama, "The Palace" as the king's younger carefree brother Prince George. He then played the character of Edmund Sparkler in the 2008 BBC version of Charles Dicken's "Little Dorrit". In the 2011 film Pirates of the Caribbean: On Stranger Tides , he played the role of the Spanish King Ferdinand.