Wednesday:
7.00 p.m.: The 110-strong Ulster Unionist Party executive meets at Glengall Street in Belfast.
7.15 p.m.: Mr David Trimble emerges from the meeting to declare the party would not participate in the d'Hondt procedure to appoint ministers to the North's powersharing executive.
Yesterday:
10.15 a.m.: The First Minister announces at a press conference in Belfast that the UUP would be boycotting the Stormont Assembly sitting. "We have decided that it is premature to form a shadow executive," Mr Trimble says. "The process should not be crashed. It should be parked, which will lead to a review."
10.28 a.m.: The Deputy First Minister, Mr Seamus Mallon, takes a call on his mobile phone from the British Prime Minister as he enters the Assembly chamber.
10.30 a.m.: Assembly Speaker Lord Alderdice opens the meeting to nominate ministers to the executive.
10.35 a.m.: Democratic Unionist Party motion calling for expulsion of Sinn Fein for 12 months is rejected due to a shortage of backers. The Speaker calls for a 15-minute recess to enable parties to study new standing orders sent by the Northern Ireland Secretary on the system of appointing ministers.
10.50 a.m.: Lord Alderdice provokes laughter when he turns to the 28 empty Ulster Unionist seats and calls on the absent Mr Trimble to begin his ministerial nominations - and gives him five minutes to do so.
10.55 a.m.: Mr John Hume nominates Mr Mark Durkan as the SDLP's first ministerial appointment.
11.00 a.m.: The Rev Ian Paisley is called on to nominate a Democratic Unionist minister. He asks for a 15-minute recess, after which he refuses to nominate in a show of protest at the presence of Sinn Fein.
11.15 a.m.: Mr Gerry Adams puts forward Ms Bairbre de Brun as Sinn Fein's first minister. The UK Unionists and the Alliance party refuse to nominate anyone. The SDLP and Sinn Fein are left to fill all of the 10 ministerial posts, Mr Martin McGuinness getting the agriculture and rural development portfolio.
11.48 a.m.: Lord Alderdice announces the ministerial appointments cannot stand because all come from the nationalist side.
11.50 a.m.: Mr Seamus Mallon resigns as Deputy First Minister, launching an attack on the UUP. He accuses it of using the political crisis to "bleed more concessions out of the governments - to bleed this very process dry".
Leaders of all other parties present follow with their own statements. Mr Adams says Mr Mallon's resignation is unfortunate and Mr Trimble's position untenable. Dr Paisley says the whole day's proceedings have been a "farce" but he adds that it "has been a good day for Northern Ireland. Democracy has triumphed and there are no IRA men in the government of Northern Ireland."
12.30 p.m.: In the House of Commons, Dr Mo Mowlam makes an emergency statement announcing a review of the workings of the Belfast Agreement. Mr Tony Blair and the Taoiseach, Mr Ahern, are to meet next week to set out the "nature, agenda and timetable" of review, she says.
1.25 p.m.: Back at Stormont, Lord Alderdice adjourns the Assembly and says Dr Mowlam has instructed that it cannot meet again until she decrees.