Which British prime minister was known as the 'Iron Duke'?

The Duke of Wellington was the British prime minister known as the “Iron Duke.”

Arthur Wellesley, 1st Duke of Wellington, earned the nickname because of his firm discipline, unwavering manner and reputation for strict control over his army. He served as prime minister twice, first from 1828 to 1830 and again briefly in 1834.

Wellington became famous as a military commander during the Napoleonic Wars. He led British and allied forces in the Peninsular War and defeated Napoleon Bonaparte at the Battle of Waterloo in 1815, alongside Prussian forces commanded by Gebhard Leberecht von Blücher.

The nickname does not mean that Wellington was literally made of iron. It reflected both admiration and criticism: supporters saw strength and resolve, while opponents portrayed him as stubborn and politically inflexible. The title “Duke of Wellington” refers to Wellesley’s peerage, while “Iron Duke” is the familiar nickname.