Peter Robinson had been first minister for less than two years
The DUP leader and Northern Ireland First Minister Peter Robinson has lost his East Belfast seat to Naomi Long of the Alliance Party.
The result is likely to be the biggest shock of the general election in Northern Ireland and one of the biggest surprises anywhere in the UK.
He polled 11,306 votes, more than a thousand behind Ms Long, who polled 12,839.
It is a massive blow to Mr Robinson, who has endured a troubled year following revelations about his wife's financial dealings and his own involvement in a land deal.
In 1971 Mr Robinson was one of the founder members of the Democratic Unionist Party (DUP).
For almost 30 years he was deputy to Ian Paisley before taking the party leadership in 2008. Later that year, he became first minister.
In January 2010, it was revealed that his wife had tried to kill herself while suffering depression after an affair.
On 11 January, Mr Robinson announced he was standing down as first minister for up to six weeks, with DUP colleague Arlene Foster taking the job on an interim basis.
He endured further media scrutiny later in the year when the BBC revealed that he had bought a piece of land near his garden from a developer for £5.
The land deal enabled the Robinsons to sell part of their back garden for nearly £460,000.
The First Minister, who sold the same piece of land to another developer for £5, denied any doing anything wrong.
Mr Robinson and his wife, Iris, who became Strangford MP in 2001, have three children.
He said they would try to save their marriage of almost 40 years.
Mr Robinson, who has been first minister since June 2008, said he would continue in his job.
The death of a school friend, Harry Beggs, killed in an IRA bombing at Northern Ireland Electricity headquarters, spurred the young Mr Robinson to enter politics.
He won the East Belfast parliamentary seat in 1979, overturning an Ulster Unionist majority of 17,000. He became DUP deputy leader a year later.
As deputy, he built a reputation as a canny strategist, plotting the DUP's election campaigns.
In the mid 1980s, he played a leading role in the joint unionist campaign against the Anglo Irish Agreement, a treaty which gave the Dublin government a greater say in Northern Ireland.
This led to the most controversial episode in his career when he led 500 loyalists in an "incursion" into the village of Clontibret in the Irish Republic.
He later admitted unlawful assembly. Later that year, he was photographed wearing a beret at a rally of the paramilitary Ulster Resistance movement.
But alongside the protest politics, the East Belfast MP remained ready to chart a way forward.
Mr Robinson was Ian Paisley's deputy for 28 years
He drew up a "Unionist Task Force" report together with members of the more moderate Ulster Unionist Party.
In 1988, he participated in a meeting in the German city of Duisburg with other local parties at a stage when the formal political process remained frozen.
Together with the rest of the DUP, Peter Robinson opposed the 1998 Good Friday Agreement, honing in on aspects like the release of paramilitary prisoners.
But he took office as minister for regional development, refusing to attend Stormont Executive meetings, but impressing his civil servants with his grasp of the detail of his brief.
He claimed credit, amongst other things, for introducing free travel for the elderly.
When the DUP became the main unionist party, Peter Robinson emerged as one of the party's most influential negotiators in the talks that led to the 2006 St Andrews Agreement.
He worked hard to limit the ability of ministers in a future executive to act as "independent warlords".
After the restoration of devolution in May 2007, he took the finance ministry and helped make revitalising the local economy the main theme of the new Stormont Executive's programme for government.
Peter Robinson was the DUP's main strategist
In his first budget, Mr Robinson froze the Stormont regional rate - a reminder that, as a local councillor in Castlereagh, he had long been a champion of keeping rates low and paring back on expenditure.
Following Ian Paisley's resignation he became First Minister in the Northern Ireland Executive which involved working closely with Sinn Fein's Martin McGuinness, the Deputy First Minister.
There was a stark contrast between how Mr Paisley and Mr Robinson got on with the Sinn Fein man.
Where the Paisley-McGuinness relationship was surprisingly jovial, the Robinson-McGuinness relationship was strained.
The two men clashed publically in December over their disagreement about the timing for the devolution of policing and justice powers.
Mr Robinson has a reputation as an political strategist. However, in the party's first election under his leadership, they suffered a disastrous performance.
They lost a large chunk of their support in the 2009 European election to the ex-DUP hardliner Jim Allister.
Ironically Mr Allister had been brought in from the political cold by Mr Robinson when he picked him to replace Ian Paisley as an MEP.