Founded:by Ian Paisley in 1971
Deputy leader:Nigel Dodds
Political position:In the past the DUP has billed itself as “right-wing in the sense of being strong on the constitution", but “to the left on social policy"
Size:It is the largest party in the Northern Ireland Assembly and the fifth-largest party in the House of Commons with 10 seat
Need to know
The DUP is the largest unionist political party in Northern Ireland but one of the smaller parties in the House of Commons.
They became very important following the result of the 2017 General Election, where no one party had an overall majority.
2017 manifesto key points
Restore a working Assembly and Executive
Support continued increases in the National Living Wage
Support proposals to further increase the personal tax allowance
Support the maintenance of the pensions triple lock
Resist any assault on universal benefits
Support the continuation of the UK’s independent nuclear deterrent
Work to get the best Brexit deal for Northern Ireland
Foster has been leader of the DUP since December 2015 and served as First Minister of Northern Ireland from January 2016.
Ms Foster and her husband Brian have three children. Before entering politics the 46-year-old, born Arlene Kelly in Roslea, County Fermanagh, trained as a lawyer.
She has held some of the most high-profile posts in Northern Ireland, having previously served as environment minister, enterprise minister and finance minister.She also served as acting first minister for short periods in 2010 and 2015.
Those who know her say her tough, determined character was forged by the experiences of her childhood when, at the age of eight, her father, a part-time policeman, was shot and injured by the IRA on the family farm.
When she was a teenager in 1988, a bomb exploded under her school bus as it was being driven by a part-time soldier in the Army's Ulster Defence Regiment. Another girl, sitting close to her, was seriously injured by the blast.
Mrs Foster was elected MLA for Fermanagh and South Tyrone for the Ulster Unionist Party (UUP) in 2003, but weeks later, she joined the DUP, along with Jeffrey Donaldson, another defector from the UUP, following splits over the direction the Ulster Unionists had been taking under David Trimble's leadership.
Profile | Arlene Foster
Leader of the Democratic Unionist Party
Born:3 July 1970 (age 46)
From:Born and raised in South Fermanagh, Northern Ireland
Education:Bachelor of Laws degree at Queen’s University, Belfast
Before politics:Private practice solicitor
First Minister of Northern Ireland (2016–2017)
Leader of DUP (2015–2017)
Minister of Finance and Personnel (2015–2016)
Minister of Enterprise, Trade and Investment (2008–2015)
Minister of the Environment (2007–2008)
Joined DUP (2004)
Resigned Ulster Unionist Party (2003)