He was promoted Lieutenant and Captain in 1760; his eldest brother, Thomas, held the same rank in the same regiment at the time.

[2] Both John and Thomas held the ranks of Captain and Lieutenant-Colonel in the Guards at the onset of the American Revolution in 1776.

Thomas was among the first to be dispatched for service in America, but he was killed in 1778 during a confrontation with an American privateer while on his way back to Britain.

[3] John, however, was deployed to America in April 1779,[3] where he participated in several skirmishing campaigns conducted by the Guards throughout that year.

He was promoted Colonel in 1780, and succeeded Edward Mathew as Brigadier-General, temporarily commanding the Brigade of Guards in February 1780.

They had five children:[1] His eldest son, Charles, Viscount Andover, died following a hunting accident in January 1800 near Norwich.