Lieutenant (1757), colonel (1760) in British army; served with distinction in Seven Years’ War. M.P. (1760), but succeeded to the House of Lords (1761) before he could take his seat. First Lord of Trade (1763). Secretary of state for the southern department, including colonial affairs (1766-68). Secretary of state for home affairs (March-July 1782). Prime minister (July 1782-February 1783). Favored a conciliatory policy towards America. Friend of Franklin, with whom he corresponded about moral and natural philosophy as well as politics.
Irish. Son of John Fitzmaurice (later Petty), 1st Earl of Shelburne, and Mary (Fitzmaurice) Petty. Educated at Christ Church College, Oxford. Married (1) Lady Sophia Carteret (1765); two sons. Married (2) Lady Louisa Fitzpatrick (1779); two children. Created Marquess of Lansdowne (1784).