I. William Petty, first marquis of, better known as the earl of Shelburne, a British statesman, born May 2, 1737, died May 2, 1805. In early life he entered the army, and served with distinction under Prince Ferdinand in the seven years' war. Upon the death of his father in 1761, he took his seat in the house of lords; and upon the formation of the Gren-ville ministry in April, 1763, he was appointed president of the board of trade, with a seat in the cabinet, although he was not then 26 years of age. In this capacity he distinguished himself by a conciliatory policy toward America, and by his opposition to the plans proposed for taxing the colonies, thereby incurring the hostility of the king and of his colleagues. Upon the remodelling of the cabinet in September he resigned office, and thenceforth attached himself to the policy and fortunes of Mr. Pitt, who, upon assuming the reins of government in 1766, made him secretary of state for the southern department, which included the colonies. He here renewed his endeavors to remove all causes of complaint between the colonies and the mother country, but was constantly thwarted by Townshend, the duke of Grafton, and others of his colleagues, who during the illness of Pitt, now become earl of Chatham, had acquired a predominating influence in the cabinet.
Not choosing to resign until he could advise with Chatham, he was dismissed by the king in October, 1768; and thenceforth, during the Grafton and North administrations, he proved himself one of the ablest and most active opponents of the ministry in the upper house. Upon the resignation of Lord North in March, 1782, he took office under the marquis of Rockingham: and upon the death of the latter in July of that year he was intrusted by the king with the formation of a new ministry. The new premier had to encounter the opposition of the Fox party, who were disappointed that the duke of Portland had not received office; and the coalition between these and the adherents of Lord North compelled him to resign in February, 1783. But during the seven months that he held office the defence of Gibraltar and the victories of Hood and Rodney added lustre to the British arms; and the preliminaries for peace with America and for the acknowledgment of the independence of the United States were concluded, notwithstanding he had joined Lord Chatham in expressing the strongest disapprobation of the latter measure. From this period he withdrew almost wholly from public life.
In 1784 he was created marquis of Lansdowne. Lord Shel-burne was considered one of the most liberal and accomplished statesmen of his time, and probably carried out more fully than any of his contemporaries the principles inculcated by the elder Pitt.
II. Henry Petty-Fitzmaurice, third marquis of, second son of the preceding, bom July 2, 1780, died Jan. 81, 1863. He was educated at Westminster, Edinburgh, and Trinity college, Cambridge, where he graduated in 1801. Upon coming of age, being then known as Lord Henry Petty, he entered parliament for the borough of Calne, succeeded to the representation of Cambridge university on the death of Mr. Pitt, and under Grenville and Fox (1806-7) was chancellor of the exchequer. He supported the leading measures of the liberal party, but retired with his colleagues in 1807; and succeeding to his title two years later, on the demise of his brother, he became one of the whig leaders in the house of lords. He was an earnest advocate of Catholic emancipation and the abolition of slavery, and was one of the first to urge the necessity of parliamentary reform and free trade. After 20 years' exclusion from a participation in the administration of public affairs, he was in 1827 home secretary both under Canning and in the short - lived cabinet of Viscount Goderich; was president of the council in Earl Grey's ministry from November, 1830, till November, 1834, and in Melbourne's from April, 1835, till September, 1841. He accepted the same office again under Lord John Russell's administration in July, 1846, and held it till February, 1852. Upon the formation of the Aberdeen cabinet in the succeeding December he accepted a seat in the cabinet without office, which he occupied till February, 1858, when he retired from public life.