Earl of Durham is a title in the Peerage of the United Kingdom. It was created in 1833 for the prominent Whig politician and colonial official John Lambton, 1st Baron Durham. Known as "Radical Jack", he played a leading role in the passing of the Great Reform Act of 1832. As Governor General of British North America he was the author of the famous Report on the Affairs of British North America, known in Canada as the Durham Report. Lambton had already been created Baron Durham, of the City of Durham and of Lambton Castle in the County Palatine of Durham, in 1828, and was created Viscount Lambton at the same time as he was raised to the earldom. These titles are also in the Peerage of the United Kingdom.
He was succeeded by his eldest surviving son, the second Earl. He served as Lord-Lieutenant of County Durham from 1854 to 1879. On his death the titles passed to his eldest twin son, the third Earl. He was Lord-Lieutenant of County Durham from 1884 to 1928 and was made a Knight of the Garter in 1909. He died childless and was succeeded by his younger twin brother, the fourth Earl. He represented South Durham and South East Durham in the House of Commons. His grandson, the sixth Earl, was a Conservative politician. He disclaimed his peerages shortly after succeeding his father in 1970, but continued improperly to style himself Viscount Lambton. As of 2014 the titles are held by his only son, the seventh Earl, who succeeded in 2006. Before succeeding in the earldom he styled himself Lord Durham to avoid confusion with his father.