[1] He entered the Army on 27 August 1779 with a commission as cornet in the 11th Dragoons, and in 1782 was made aide-de-camp to General Richard Whyte at Jersey.
[2] FitzRoy was granted brevet rank as colonel on 26 January 1797,[3] and in 1799 commanded the grenadier company of the 1st Foot Guards during the expedition to Holland.
On 25 March 1805 he was made colonel of the 25th Regiment of Foot, on 27 August 1809 appointed regular equerry to the King,[4][5] and on 25 July 1810 he was promoted lieutenant-general.
Princess Amelia of the United Kingdom fell in love with Charles Fitzroy, desiring to marry him.
It was hoped that such discretion would prevent the King from discovering the liaison, which may have risked sending him into one of the bouts of mental illness to which he was becoming increasingly prone.