He succeeded to the title of 4th Baronet Courtenay, 2nd Viscount Courtenay of Powderham Castle and 8th Earl of Devon (Created c.1553) on 16 May 1762 upon the death of his father.
Family
He married Lady Frances Clack (d. 25 March 1782) on (7 May 1762) with whom he had the following children.
Caroline-Eustatia Courtenay (b. 26 March 1775) married Colonel Charles Morland on 14 June 1812.
Matilda-Jane Courtenay (b. 6 July 1778) married John Lock.
Sophia Courtenay (b. 25 January 1780) married Lieutenant-Colonel Nathaniel Foy in December 1804.
Louisa Augusta Courtenay (d. 8 February 1825) married Lord Edward Somerset on 17 October 1805.
And one illegitimate child. The mother of this child is unknown, all that is known is the child had the surname "Vane" and she was "akin" to Sir Henry Vane the Younger who died of beheading in 1662 over one hundred years earlier].
Mary Ann Vane (26 February 1784 – c. 1848–1852) married Louis Chevalier, Seigneur du Saint-Paul of Quebec in approximately 1799. They had three children, Mary Sophia Chevalier, Philip David Chevalier and Mary Anne Chevalier.