Early years and successes
The party was established in 1971 by
Ian Paisley and
Desmond Boal and other members of the
Protestant Unionist Party. Since its foundation it has won seats at local council,
Northern Ireland, UK and European level. It won eight seats in the
Northern Ireland Assembly of 1973–1974, where it opposed the formation of a power-sharing executive made up of
Irish nationalists following the
Sunningdale Agreement. The DUP were more
Ulster loyalist than the
Ulster Unionist Party (UUP). And its establishment arguably stemmed from insecurities of the
Ulster Protestant working class.
 Paisley was elected one of Northern Ireland's three
European Parliament members at the first elections in 1979 and retained that seat in every European election until 2004. In 2004 Paisley was replaced as the DUP MEP by
Jim Allister, who resigned from the party in 2007 while retaining his seat.
The DUP also holds seats in the
House of Commons of the United Kingdom, and has been elected to each of the Northern Ireland conventions and assemblies set up since the party's creation. It has long been the principal rival to the other major unionist party, the UUP (known for a time in the 1970s and 1980s as the Official Unionist Party (OUP) to distinguish it from the then multitude of other unionist parties, some set up by deposed former leaders). The DUP's main opponent is
Sinn Féin and its main rival for votes is the
Ulster Unionist Party.
The DUP was originally involved in the negotiations under former
United States Senator
George J. Mitchell that led to the
Good Friday Agreement, but withdrew in protest when Sinn Féin, an
Irish republican party with links to the
Provisional Irish Republican Army (IRA), was allowed to participate while the IRA retained its weapons. The DUP opposed the Agreement in the
Northern Ireland Good Friday Agreement referendum, in which the Agreement was approved with 71.1% of the electorate in favour.
The opposition was based on a number of reasons, including:
The Good Friday Agreement relied on the support of a majority of unionists and a majority of nationalists in order for it to operate.2003 Assembly Election, the DUP argued for a "fair deal" that could command the support of both unionists and nationalists. After the results of this election the DUP argued that support was no longer present within unionism for the Good Friday Agreement. They then went on to publish their proposals for devolution in Ireland entitled Devolution Now.
These proposals have been refined and re-stated in further policy documents including Moving on
 and Facing Reality.
 The DUP holds the view that any party which is linked to a
terrorist organisation should not be eligible to hold Government office.
The DUP fought the resulting election to the
Northern Ireland Legislative Assembly and took two seats in the multi-party power-sharing executive. While serving as ministers, they refused to sit in at meetings of the Executive Committee in protest at Sinn Féin's participation. The Executive ultimately collapsed over an alleged IRA espionage ring at
In the delayed Northern Ireland Assembly election of 2003, the DUP became the largest political party in the region, with 30 seats. In 2004, it became the largest Northern Ireland party at
Westminster, with the defection of former UUP MP
Jeffrey Donaldson. On 12 December 2004, English MP
Andrew Hunter took the DUP whip, giving the party seven seats, in comparison to the UUP's five, Sinn Féin's four, and the
Social Democratic and Labour Party's (SDLP) three.
2005 general election, the party reinforced its position as the largest unionist party, winning nine seats, making it the fourth largest party in terms of seats in the British House of Commons behind Labour, the Conservatives and the Liberal Democrats. In terms of votes, the DUP was the fourth largest party on the island of Ireland.
local government election of 2005, the DUP also emerged as the largest party at local government level with 182 councillors across Northern Ireland's 26 district councils.
 The DUP has a majority of the members on both
Castlereagh Borough Council, which has long been a DUP stronghold and is home to party leader
Peter Robinson, also in
Ballymena Borough Council, home to the party's founder Ian Paisley, and finally
Ards Borough Council. As well as outright control on these councils, the DUP is also the largest party in eight of the other councils. These are
Antrim Borough Council,
Ballymoney Borough Council,
Banbridge District Council,
Belfast City Council,
Carrickfergus Borough Council,
Coleraine Borough Council,
Craigavon Borough Council and
Newtownabbey Borough Council.
On 11 April 2006, it was announced that three DUP members were to be elevated to the
House of Lords:
Wallace Browne, the former
Lord Mayor of Belfast, and
Eileen Paisley, a vice-president of the DUP and wife of DUP Leader
Ian Paisley. None, however, sit as DUP peers.
On 27 October 2006, the DUP issued a four-page letter in the Belfast Telegraph newspaper asking "Are the terms of Saint Andrew's a basis of moving forward to devolution?", with responses to be received to its party headquarters by 8 November. It was part of the party's policy of consultation with its electorate before entering a power-sharing government.
On 24 November 2006, Ian Paisley refused to nominate himself as
First Minister of Northern Ireland designate. There was confusion between all parties whether he actually said that if Sinn Féin supported policing and the rule of law that he would nominate himself on 28 March 2007 after the Assembly elections on 7 March 2007. The Assembly meeting was brought to an abrupt end when the building had to be evacuated because of a security breach. Paisley later released a statement through the press office stating that he did in fact imply that if Sinn Féin supported policing and the rule of law, he would go into a power-sharing government with them. This was following a statement issued by 12 DUP MLAs stating that what Ian Paisley had said in the chamber could not be interpreted as a nomination.
In February 2007, the DUP suggested that it would begin to impose fines up to
£20,000 on members disobeying the party whip on crucial votes.
On 24 March 2007 the DUP party executive overwhelmingly endorsed a resolution put to them by the party officers which did not agree to an establishment of devolution and an executive in Northern Ireland by the Government's deadline of 26 March, but did agree to setting up an executive on 8 May 2007.
On 27 March 2007, the party's sole Member of the European Parliament (MEP),
Jim Allister, resigned from the party, in opposition to the decision to enter a power-sharing government with Sinn Féin. He retained his seat as an independent MEP as leader of his new hard-line anti-St Andrews Agreement splinter group that he formed with other disaffected members who had left the DUP over the issue,
Traditional Unionist Voice, a seat which he retained until
Diane Dodds won the seat back for the DUP in 2009. MP
Gregory Campbell warned on 6 April 2007 that his party would be watching to see if benefits flow from its agreement to share power with Sinn Féin.
On 31 May 2008, the party's central Executive Committee met at the offices of
Castlereagh Borough Council where Ian Paisley formally stepped down as party leader and Peter Robinson was ratified as the new leader, with Nigel Dodds as his deputy.
On 11 June 2008 the party supported the government's proposal to detain terror suspects for up to 42 days, leading to
The Independent dubbing all of the party's nine MPs as part of "Brown's dirty dozen".
The Times reported that the party had been given "sweeteners for Northern Ireland" and "a peerage for the Rev Ian Paisley", amongst other offers, to secure
Gordon Brown's bill.
Members of the DUP were lambasted by the press and voters, after MPs' expenses reports were leaked to the media. Several newspapers referred to the "Swish Family Robinson" after Peter Robinson, and his wife Iris, claimed £571,939.41 in expenses with a further £150,000 being paid to family members.
 Further embarrassment was caused to the party when its deputy leader, Nigel Dodds, had the highest expenses claims of any Northern Ireland MP, ranking 13th highest out of all UK MPs.
 Details of all MPs' expenses claims since 2004 were published in July 2009 under the
Freedom of Information Act 2000.
In January 2010, Peter Robinson was at the centre of a
high-profile scandal relating to his 60-year-old MP/MLA wife
Iris Robinson's infidelity with a 19-year-old man, and alleged serious financial irregularities associated with the scandal.
2010 General Election, the party suffered a major upset when its leader, Peter Robinson, lost his
Belfast East seat to
Naomi Long of the
APNI on a swing of 22.9%. However, the party maintained its position elsewhere, fighting off a challenge from the
Ulster Conservatives and Unionists – New Force in
Antrim South and
Strangford and from
Traditional Unionist Voice in
The DUP were strongly criticised after the
Red Sky scandal in which DUP ministers attempted to influence a decision at a meeting of the
Northern Ireland Housing Executive. The decision related to a £8 million contract of east Belfast firm Red Sky. The Housing Executive cancelled Red Sky's contract after a BBC Spotlight investigation into the company, which was shown to be overcharging taxpayers. The DUP cited "sectarian bias" in relation to the decision.
 The party suspended DUP councillor
Jenny Palmer, who sat on the Executive board, after she confessed that DUP special adviser Stephen Brimstone pressured her into changing her vote at the meeting.
2015 General Election, when the result was expected to be a
hung parliament, the issue of DUP and the
UK Independence Party forming a
coalition government with the
UK Conservative Party was considered by
Nigel Farage (leader of UKIP).
 The then Deputy Prime Minister and leader of the
Nick Clegg, warned against this "Blukip" coalition, with a spoof website highlighting imagined policies from this coalition – such as reinstating the
death penalty, scrapping all benefits for under 25s and charging for hospital visits.
 Additionally, issues were raised about the continued existence of the
BBC (as the DUP, UKIP and Conservatives had made a number of statements criticising the institution)
 and support for
LGBT rights and
 However, in an interview with
BBC Radio 5 Live deputy leader of the DUP
Nigel Dodds told
BBC Newsline in 2015 that, despite opposition to same-sex marriage, the DUP was "against discrimination based on religion ... or sexual orientation".
 Additionally, David Cameron said he "totally disagreed" with the DUP on the issue of same-sex marriage and LGBT rights, claiming that "nothing I will do" would go against the principle of "the values that I have", including "equality for gay and lesbian people".
On 10 September 2015, Peter Robinson stepped aside as First Minister and other DUP ministers, with the exception of
Arlene Foster, resigned their portfolios.
On 4 October 2016, DUP leader Arlene Foster and DUP MPs held a champagne reception at the
conference, marking what some have described as an "informal coalition" or an "understanding" between the two parties to account for the Conservatives' narrow majority in the
House of Commons.
In January 2017, the
Northern Ireland Executive collapsed after
Martin McGuinness resigned in protest at the
Renewable Heat Incentive scandal, which centred on a green energy scheme that Foster set up in her capacity as Minister of Enterprise, Trade and Investment. The scheme lacked cost controls and could cost the public purse up to £490 million. Foster refused to resign or step aside during any inquiry into her role in the scheme, which led McGuinness to resign. His resignation caused snap elections after
Sinn Féin refused to re-nominate a deputy First Minister. The
election resulted in a loss of 10 seats for the DUP, leaving them only one seat and 1,200 votes ahead of Sinn Féin, a result described by the
Belfast Telegraph as "catastrophic".