2007: By 2007 the DUP had eclipsed the UUP electorally and Sinn Féin had done the same to the SDLP, leading the two parties into an historic powersharing arrangement in the North.
This followed face-to-face talks between Sinn Féin leader Gerry Adams and DUP leader Ian Paisley.
Dr Paisley and Sinn Féin chief negotiator and former IRA leader Martin McGuinness were dubbed the “Chuckle Brothers” in the weeks after they first signed up to share power.
Stunning virtually everyone, the first minister and Deputy First Minister enjoyed what Mr McGuinness called a “cordial and civilised” working relationship, after a political party history of mutual hatred.
So cordial and civilised was the relationship that almost every time the two held press conferences or attended political events together they were seen joking and laughing. Mr McGuinness said they had not exchanged an angry word in the months they led the Stormont executive together.
2008: Dr Paisley stands down as first minister and as leader of the DUP, to be succeeded by Peter Robinson. This is a much more workmanlike relationship. 2009: The two parties fall out over the devolution of policing and justice powers to Northern Ireland and Mr McGuinness warns of an impending full-blown crisis.
2010: Mr Robinson stands down temporarily as first minister but remains as DUP leader as controversy engulfed the party over his wife Iris Robinson's personal and financial issues. Talks continue on devolution, and eventual agreement is reached.
2012: Rising tension between Sinn Féin and the DUP flares into protests by loyalists after Belfast City Council decides to limit the number of days the British flag flies from City Hall. Loyalists block roads and some protests turn into riots.
2013: In a swipe at Sinn Féin, the DUP withdraws its support for the transformation of the Maze prison, where paramilitary prisoners were held during the Troubles, into a centre for peace and conflict resolution.
Former US envoy to the North Richard Haass is brought in as a chairman of an independent all-party group to deal with flags, emblems and protests and other controversies linked to the past. Lengthy talks ensue without agreement.
2014: A collapse of the executive is threatened when Sinn Féin refuses to implement social welfare reforms demanded by the British government in London. After almost three months of talks, agreement is reached at the end of 2014 in what is called the Stormont House Agreement, to deal with the budget and the failure to implement welfare reforms.
The agreement also includes new structures to deal with unsolved killings from the Troubles.
2015: The already fraught relationship between the DUP and Sinn Féin reaches a new low over the killing of two former IRA members in August. Then PSNI chief constable George Hamilton says the IRA was involved in the killings and states that the IRA still exists.
A further welfare reform row then breaks out. Another bout of talks ensues lasting 10 weeks, leading to the Fresh Start Agreement. This involves the Irish Government, the British government, the DUP and Sinn Féin on a way to deal with paramilitarism and welfare reform.
2016: Mr Robinson resigns as first minister and DUP leader. He is succeeded by Arlene Foster, a former Ulster Unionist, after the DUP's Nigel Dodds decides to focus on his role as a Westminster MP.
A crisis hits after questions are raised about a renewable energy scheme to persuade businesses and farmers to move from fossil fuels to biomass energy. Ms Foster was minister for energy when the Renewable Heat Incentive (RHI) scheme – known as “cash for ash” – was introduced, which could cost taxpayers £490 million.
Mr McGuinness resigns when Ms Foster refuses to step aside temporarily pending an investigation.
Assembly elections are expected to be called for the end of February are early March.
