Peter Hain was born to South African parents in Nairobi, Kenya. His parents were anti-Apartheid activists, for which they were made "banned persons", briefly jailed, and prevented from working. In 1966 the family fled the country and settled in London, where Peter's father Walter Hain made a living as an architect. Peter became chairman of the Stop the Seventy Tour Camapign which disrupted tours by the South African Rugby Union and cricket teams in 1969 and 1970. In 1976 he was tried for, and acquitted of, a 1974 bank robbery, allegedly having been framed by South African intelligence agents. He joined the Liberal Party and was elected president of the Young Liberals, but in 1977 defected to Labour. The same year, he was a founder of the Anti-Nazi League.
Hain worked as a researcher for the Union of Communication Workers, rising to become their head of research before being elected to the House of Commons at a by-election in 1991. In 1995 he became a Labour whip and in 1996 became shadow employment minister. After Labour's victory in the 1997 general election he joined the government, first at the Welsh Office, then as minister for Africa at the Foreign and Commonwealth Office. He moved briefly to the Department of Trade and Industry before returning to the Foreign Office as minister for Europe. In 2002 he joined the Cabinet as Secretary of State for Wales, but continued to represent the UK at the Convention on the Future of Europe. In June 2003 he was made Leader of the House of Commons in a cabinet reshuffle, but retained the Wales portfolio.