Peter Mandelson, English journalist and politician, Secretary of State for Northern Ireland
Peter Benjamin Mandelson, Baron Mandelson (born 21 October 1953) is a British Labour Party politician who served as First Secretary of State from 2009 to 2010. He was President of the Board of Trade in 1998 and from 2008 to 2010. He is the president of international think tank Policy Network, honorary president of the Great Britain–China Centre, and chairman of strategic advisory firm Global Counsel. Mandelson is often referred to as a Blairite.

From 1985 to 1990, Mandelson served as Labour's Director of Communications. He was one of the first to whom the term 'spin doctor' was applied and gained the nickname 'the Prince of Darkness' because of his 'ruthlessness' and 'media savvy'. He served as Member of Parliament (MP) for Hartlepool from 1992 to 2004 and held a number of Cabinet positions under Prime Ministers Tony Blair and Gordon Brown. He was the European Commissioner for Trade between 2004 and 2008.

Mandelson was one of several key people responsible for the rebranding of the Labour Party as New Labour before its victory in the 1997 election. He was twice forced to resign from the Cabinet before leaving Parliament to take up an appointment as a European Commissioner. He later rejoined the Cabinet for a third time after being created a life peer, sitting on the Labour benches in the House of Lords. He is the only person to have held the position of First Secretary of State as a Peer.