Wellington’s experiences abroad prevented him from ever becoming a party politician. Though he joined the earl of Liverpool’s Tory cabinet as master general of the ordnance, he exempted himself from automatically opposing a subsequent Whig government: “a factious opposition,” he argued, “is highly injurious to the interests of the country.” His identification with the party of law and order, however, increased when postwar discontent boiled over in the Peterloo Massacre at a Manchester demonstration for parliamentary reform and the Cato Street Conspiracy, a plot to murder the cabinet organized by Arthur Thistlewood. The popular George Canning succeeded Viscount Castlereagh as foreign secretary in 1822. Despite Canning’s antipathy to the congress system, Wellington himself overbore George IV’s personal objections to him, believing that the system was by now unshakably established. When Canning extricated Britain from its European commitments, Wellington was left to bitter self-reproach. His own diplomatic failures at the Congress of Verona (1822), at which he vainly sought to heal dissension among the European allies, and in Russia (1826) increased his chagrin. Straightforward to a fault, Wellington was unsuited to carrying out Canning’s subtle policies, but he gained respect abroad as an honest man.

In 1825 Wellington turned to Ireland’s problem, formulating it as a basic dilemma: political violence would end only after the Catholics’ claim to sit in Parliament, known as Catholic Emancipation, had been granted; yet the Protestant Ascendancy, or establishment, must be preserved. He worked privately at a solution, by which a papal concordat to ensure at least minimum control of Catholic clergy would be the precondition of Emancipation. When Canning, an unqualified Emancipator, became prime minister in April 1827, however, Wellington felt that Protestant Ascendancy was in jeopardy. He and Robert Peel headed a mass exodus from the government, Wellington also resigning his command of the army. This action was interpreted as pique at the king’s choosing his rival for prime minister. In denying the allegation, Wellington rashly asserted that he, a soldier, would be “worse than mad” to consider himself fit for the premiership. After Canning’s death that August, he resumed his army command. Within five months Canning’s successor, Viscount Goderich, had given up the task, and on January 9, 1828, the king summoned the duke of Wellington.

Years as prime minister

The duke’s aim was to achieve a strong and balanced government by reuniting the Tory Party. Having reluctantly resigned again as commander in chief, he invited the Canningites, headed by William Huskisson, to serve, while dropping the ultra-Tories as incompatible with his policy of moderation. With the right wing thus alienated, a chasm began to open on the left. The opposition’s demand for extensive reforms met with sympathy from Huskisson’s group. Wisely, the duke retreated, first on a church issue, himself reforming the Test and Corporation Acts that penalized Nonconformists, and again on a Corn Law (prohibiting importation of cheaper foreign grains) question, introducing a more liberal reform than he and the agricultural interest desired. Shortly afterward, however, he collided head-on with the Huskissonites on parliamentary reform; the whole group resigned in May. A further crisis immediately arose during the by-election in Clare, Ireland, where William Vesey-Fitzgerald, Huskisson’s ministerial successor, defending his seat, was defeated by Daniel O’Connell, the Irish Catholic leader. The defeat of Vesey-Fitzgerald, a popular pro-Catholic, carried an alarming moral for the duke: until Emancipation was granted, no Tory would win in southern Ireland. There might well be civil war. In August 1828 Wellington therefore undertook the most exacting political duty of his career—the conversion of George IV, Peel, who was now leader of the Commons, and a majority of Tories to Catholic Emancipation, a reform that they had hitherto regarded as anathema. It took six months of indefatigable persuasion behind closed doors to win over the king. Peel’s position was equally problematic—as a publicly declared Protestant, he clung to the idea of supporting Emancipation only from the back benches—but finally Wellington’s patience and Peel’s generosity prevailed, and he agreed to continue leading the Commons. A number of ultra-Tories defied to the last Wellington’s order to “right-about face,” but the majority of the party obeyed. So in April 1829, though the Tories were split, Catholic Emancipation became law, the duke’s greatest political victory, with melodrama being added by his fighting a duel with an abusive ultra-Tory, the earl of Winchilsea.

Wellington has sometimes been criticized for inconsistency. It now appears that he was merely secretive in not taking the public into his confidence much earlier. His willingness for some form of Emancipation by 1825 might with advantage have been disclosed.

A demand for further changes, already stimulated by Wellington’s own achievements, was powerfully reinforced by countrywide hardship during 1829–30 and canalized by Charles Grey, the 2nd Earl Grey, the Whig leader, into fresh moves for parliamentary reform that would allow industrial towns like Birmingham to have a voice in Parliament, in place of pocket boroughs owned by the nobility and gentry. Expression of dissatisfaction with Wellington’s fatalistic attitude toward poverty and unemployment was made possible when the accession of William IV in 1830, following George IV’s death, provided a general election. France’s bourgeois revolution that same year—the July Revolution—greatly encouraged British reformers. Though Wellington’s ministry survived, it was weakened, and Huskisson’s sudden death frustrated tentative plans for reconciliation. Wellington saw parliamentary reform not as a panacea but as constitutional suicide. A fortnight before the opening of Parliament he wrote a letter to a friend denouncing reform as ruinous and disclosing his unalterable decision to oppose it. He staggered Parliament on November 2 with an uncompromising declaration against any reform whatever. A combination of reformers and vengeful ultra-Tories defeated him on the 15th. Peel made him resign the next day. He was succeeded by Grey.

As a soldier, Wellington had shown uncanny ability in guessing what lay “on the other side of the hill.” Through lack of political imagination, however, he saw revolution beyond the hill of reform—“revolution by due course of law.” For this delusion he was deservedly called reactionary.