Lord Robert Cecil was the second son of the 2nd Marquess of Salisbury. After an unhappy childhood, he went into politics, entering the House of Commons as a Conservative in 1853.
In 1857, Cecil married Georgina Alderson, a woman of low social standing, in spite of his father's objections. The marriage proved a happy one, producing five sons and two daughters. In 1866 Cecil, now called Viscount Cranborne (due to the death of his older brother), entered the third government of Lord Derby as Secretary of State for India, but resigned the next year over the Reform Bill, which he opposed.
In 1868, on the death of his father, the new Marquess of Salisbury was raised to the House of Lords.
He returned to government again in 1874, serving once again as India Secretary in the government of Benjamin Disraeli. Gradually, Salisbury developed a good relationship with Disraeli, whom he had previously disliked and distrusted, at least partially due to the latter's Jewish origins. In 1878, Salisbury succeeded Lord Derby (son of the Prime Minister) as Foreign Secretary, in time to help lead Britain to "peace with honor" at the Congress of Berlin[?]. For this he was rewarded with the Order of the Garter.
Following Beaconsfield's death in 1881, Salisbury became the leader of the Conservative opposition, and became Prime Minister of a minority administration from 1885 to 1886. Although he was unable to accomplish much in this administration, due to his tenuous command over the Commons, the split of the Liberals over Irish Home Rule[?] in 1886 enabled him to return to power with a parliamentary majority, and, with a short break (1892-1895) to serve as Prime Minister throughout the period from 1886 to 1902.
Salisbury's expertise was in foreign affairs, and uncharacteristically, for most of his time as Prime Minister he served not as First Lord of the Treasury, the traditional position held by the Prime Minister, but as Foreign Secretary. In that capacity, he skillfully managed Britain's foreign affairs, famously pursuing a policy of "Glorious Isolation," while at home he staunchly opposed Irish Home Rule. Among the important events of his premierships was the Partition of Africa[?], culminating in the Fashoda Crisis[?] and the Boer War.