Wellington, "the iron duke," with the soldier's taste for discipline and order and the aristocrat's distrust of democratic institutions, lent his great prestige to the Tory policy of repression at home and took a cabinet post as master general of the ordnance (1819). He represented England at the Congress of Verona (1822), where he opposed intervention in the Spanish revolt, and at the conference at St. Petersburg (1826) that concerned itself with the revolt in Greece, but he was not in sympathy with the liberal foreign policy of George Canning and resigned (1827) when Canning became prime minister.
In 1828 Wellington himself reluctantly became prime minister. He bowed to public clamor and allowed the repeal of the Test Act and Corporation Act and the passage of the Catholic Emancipation bill (reforms he had previously opposed), but he lost the support of much of the Tory party as a consequence. When he declared against parliamentary reform, the ministry fell (1830), and his unpopularity subjected him to an assault by a mob. He refused to form a government in 1834, but served under Sir Robert Peel as foreign secretary (1834–35) and again (1841–46) as minister without portfolio. On the repeal of the corn laws he supported Peel, while not wholly approving his policy. In 1842 he was made commander in chief for life. He is buried in St. Paul's Cathedral.