Cameron, a descendant of King William IV, was born into a family with both wealth and an aristocratic pedigree. He attended Eton College and Brasenose College, Oxford, from which he graduated (1988) with a first-class degree in philosophy, politics, and economics. After Oxford he joined the Conservative Party Research Department. In 1992 he became a special adviser to Norman Lamont, then chancellor of the Exchequer, and the following year he undertook the same role for Michael Howard, then home secretary. Cameron joined the media company Carlton Communications in 1994 as director of corporate affairs. He stayed at Carlton until entering Parliament in 2001 as MP for Witney, northwest of London.

Cameron quickly attracted attention as the leading member of a new generation of Conservatives: young, moderate, and charismatic. He was widely compared to Labour Prime Minister Tony Blair (Blair, Tony), who had acquired a similar reputation when he entered Parliament 18 years earlier. After just two years as an MP, Cameron was appointed to his party's “front bench”—making him a leading Conservative spokesman in the House of Commons. In 2004 Howard, by then party leader, appointed his young protégé to the post of head of policy coordination, which put Cameron in charge of preparing the Conservatives' 2005 election manifesto. The party, however, suffered a heavy defeat at the polls, provoking Howard's resignation. Cameron's self-assured speech at the party's annual conference in October 2005 transformed his reputation, and he was subsequently elected Conservative leader.

Cameron sought to modernize the party and shed its right-wing image. He announced that economic stability and strong public services would be a priority over tax cuts in the next Conservative government. Under his leadership, the party grew in popularity and placed first in the 2006 local elections; it was the Conservatives' best showing at the polls in some 15 years.