Iain Duncan Smith, British soldier and politician, Secretary of State for Work and Pensions
Sir George Iain Duncan Smith (born George Ian Duncan Smith; 9 April 1954), often referred to by his initials IDS, is a British politician who served as Leader of the Conservative Party and Leader of the Opposition from 2001 to 2003. He was Secretary of State for Work and Pensions from 2010 to 2016. He has been Member of Parliament (MP) for Chingford and Woodford Green, formerly Chingford, since 1992.

The son of W. G. G. Duncan Smith, a Royal Air Force flying ace, Duncan Smith was born in Edinburgh and raised in Solihull. After education at the training school HMS Conway and Royal Military Academy Sandhurst, he served in the Scots Guards from 1975 to 1981, seeing tours in Northern Ireland and Rhodesia. He joined the Conservative Party in 1981. After unsuccessfully contesting Bradford West in 1987, he was elected to Parliament at the 1992 general election.

Following the resignation of William Hague, Duncan Smith won the 2001 Conservative Party leadership election, partly owing to the support of Margaret Thatcher for his Eurosceptic beliefs. However, many Conservative MPs came to consider him incapable of winning the next general election and, in 2003, passed a vote of no confidence in his leadership; he immediately resigned and was succeeded by Michael Howard. Returning to the backbenches, Duncan Smith became a published novelist. He then founded the Centre for Social Justice, a centre-right think tank independent of the Conservative Party, and became chair of its Social Justice Policy Group.

In May 2010, new Prime Minister David Cameron appointed him to serve in the cabinet as Secretary of State for Work and Pensions. During his tenure, he was responsible for seeing through changes to the welfare state. He resigned from the cabinet in March 2016, in opposition to Chancellor George Osborne's proposed cuts to disability benefits.