Henry Petty-Fitzmaurice, 3rd Marquess of Lansdowne

Henry Petty-Fitzmaurice, 3rd Marquess of Lansdowne (2 July 178031 January 1863), known as Lord Henry Petty from 1784 to 1809, was a British statesman. In a ministerial career spanning nearly half a century, he notably served as Home Secretary and Chancellor of the Exchequer and was three times Lord President of the Council, serving in every Whig or Liberal Ministry from 1806 to 1863.

Background and education Lansdowne was the son of Prime Minister William Petty, 1st Marquess of Lansdowne (better known as the Earl of Shelburne), by his second marriage to Lady Louisa, daughter of John FitzPatrick, 1st Earl of Upper Ossory. He was educated at Westminster School, the University of Edinburgh, and Trinity College, Cambridge.

Political career He entered the House of Commons in 1802 as member for the family borough of Calne and quickly showed his mettle as a politician. In February 1806 he became Chancellor of the Exchequer in Lord Grenville's Ministry of All the Talents, being at this time member for the University of Cambridge, but he lost both his seat and his office in 1807.

In 1809 he became the 3rd Marquess of Lansdowne, succeeding his politically disaffected elder half-brother, John Petty, in the title. The 2nd Marquess, had been obliged to leave Ireland, where the family had estates, after intelligence reports had implicated him in the United-Irish conspiracy of Robert Emmet. On the death of their father, the 1st Marquess had married his mistress by whom he had had no children.

In the House of Lords and in society the third marquess continued to play an active part as one of the Whig leaders. His chief interest was perhaps in the question of Roman Catholic emancipation, a cause which he consistently championed, but he sympathised also with the advocates of the abolition of the slave trade and with the cause of popular education. Lansdowne, who had succeeded his cousin, Francis Thomas Fitzmaurice, as 4th Earl of Kerry in 1818, took office with George Canning in May 1827 and was Secretary of State for the Home Department (Home Secretary) from July of that year until January 1828.

In his later years Lansdowne was known as "the Nestor of the Whigs" (after the wise old king of Greek mythology).