 In 1731, he succeeded his brother, Sir William Morgan, as Lord Lieutenant of Brecknockshire and Monmouthshire, and was appointed brigadier-general of the militia of those counties.At the 1734 British general election, he was returned unopposed as MP for Monmouthshire, and was returned there again at the 1741 British general election.Also in 1741 was appointed Judge Advocate General, by which he became known as "General Morgan".