Ancram was commissioned a
cornet in 1735. He was a
captain in the
31st Regiment of Foot in 1739, and transferred as such to the
1st Regiment of Foot Guards in 1741. He was subsequently made an ADC to the King and a colonel. In the same year, he was appointed
lieutenant-colonel of
Lord Mark Kerr's Regiment of Dragoons, and commanded the
cavalry on the left wing at the
Battle of Culloden in 1746 (His younger brother,
Lord Robert Kerr, was with the infantry and was the highest-ranking Government casualty of the battle). After the battle, he commanded the forces at
Aberdeen until August, and then returned to the Continent with Cumberland in December. On 1 December 1747, he succeeded Daniel Houghton as colonel of the
24th Regiment of Foot. On 11 December 1747, through the interest of his brother-in-law
Robert Darcy, 4th Earl of Holderness, he was returned as
Member of Parliament (MP) for
Richmond at a by-election in place of
Sir Conyers Darcy, who had also been returned for
Yorkshire and preferred that seat. In 1752, Ancram was appointed colonel of the
11th Regiment of Dragoons, in succession to his grand-uncle
Lord Mark Kerr. He was promoted to the rank of
Lieutenant General in 1758 and held a command under the
Duke of Marlborough during the
Raid on St Malo. ==Resignation from the Commons==