Robert Gascoyne-Cecil, 3rd Marquess of Salisbury

Robert Cecil entered the Commons in 1854 and climbed through India Office postings until Disraeli made him foreign secretary in 1878, where he helped broker the Congress of Berlin. After Disraeli died in 1881, Salisbury became Conservative leader in the Lords and first took the premiership in June 1885. When Gladstone backed Irish Home Rule the next year, Salisbury split the Liberals by allying with Unionist defectors and won the 1886 election. That second term delivered his sharpest work: Britain claimed the lion's share of African territory in the Scramble without major war. He lost in 1892, returned in 1895, then steered the empire through the brutal Boer War to another victory in 1900. He handed power to his nephew Balfour in 1902 and died the following year. Historians mark him as neurotic, pessimistic, resistant to change - his guiding belief that "whatever happens will be for the worse" - yet effective, consistently ranked in the upper tier of prime ministers.