In the 1820s, the British government was formally headed by King George IV, but in practice, was led by his Prime Ministers Lord Liverpool (1812–1827), George Canning (1827), Lord Goderich (1827–1828), and Duke of Wellington (1828–1830). This decade was largely peaceful for Britain, with some foreign intervention. The British supported the Portuguese liberals in the Liberal Wars, and supported Greek rebels in the war for independence. During this time, London became the largest city of the world, taking the lead from Beijing.