[6] He also represented Naas in the Irish House of Commons between 1795 and 1798[7] and served under William Pitt the Younger as Chief Secretary for Ireland between 1794 and 1795.

[9] He succeeded his father in the earldom on 12 January 1798, his elder brother having committed suicide in 1776, and entered the House of Lords.

On 25 June 1798, he was appointed colonel of the Dorset Militia in succession to Lord Rivers,[10] but resigned in late 1799.

[12] Lord Dorchester was a great favourite of the royal family who occasionally stayed at his estate at Milton Abbey near Weymouth.

[13] He died unmarried in Park Lane, London,[14] in March 1808, aged 61, when his titles became extinct.