At 17 he entered the British army. Through the custom of purchasing commissions, he became a lieutenant colonel at 23, but his later achievements justified his quick promotion. In the hill country of India from 1796 to 1805, he conquered Mahratta chiefs who had sworn to drive the English into the sea. In making treaties that closed the war with these tribes, he proved himself an able diplomat as well.
In 1805 he left India for the war with Napoleon in Europe. He won a notable victory in his first campaign on the French-held Spanish peninsula, but the results were lost by incompetent superiors. In 1809 he returned as commander in chief. In five years he drove Napoleon's generals from the Iberian Peninsula.
After Napoleon's first exile Wellington was in Paris as Britain's ambassador to the restored king of France. Napoleon's escape from Elba sent Wellington back into military service. Finally at Waterloo, with the aid of Prussian troops, Wellington met and vanquished Napoleon himself (see Battle of Waterloo).
For years Wellington was one of the most influential men in all of Europe. As prime minister of Great Britain from 1828 to 1830, however, he was less successful. He was an aristocrat who failed to note the changing times. He dismissed without consideration the demand for parliamentary reform and the extension of the right to vote as the work of agitators. He was forced to resign and had to protect his house from a mob. When the angry passions of the times subsided, people granted that Wellington, while not always an able statesman, had tried to do what he believed best for the nation. He died at Walmer Castle in Kent, England, on Sept. 14, 1852.