3pm, 2 December 1999. Ulster takes control of its own future

The suspicion is growing, in suspicious bitter old Belfast, that this arrangement is actually going to work, that it has the power and the potential to consign the Troubles to history and allow Northern Ireland to start afresh.

The suspicion is growing, in suspicious bitter old Belfast, that this arrangement is actually going to work, that it has the power and the potential to consign the Troubles to history and allow Northern Ireland to start afresh.

The sense grew throughout yesterday that the vivid blur of activity - not just political but constitutional as well - was so breathtaking in its scope that it will provide all sides with enough gain to outweigh the pain. It is the solution that attempts to redress the lethal flaws in the measure that partitioned Ireland nearly 80 years ago - the measure that filled the reservoirs of bitterness, which burst into the Troubles.

In one unprecedented day Unionists and republicans sat down together in a powersharing cabinet; power arrived in Belfast from Westminster after a quarter century of political sterility; and new north-south and British-Irish agreements came into force.

The 1920 Act, which set up Northern Ireland, was amended and the 1985 Anglo-Irish Agreement disappeared. In Dublin, De Valera's long-revered Irish constitution was modernised after 60 years, with Bertie Ahern, the Irish Prime Minister, signing the changes into effect watched by his entire cabinet.

In London, the Irish President, Mary McAleese, lunched with the Queen, who in another gesture of reconciliation may soon be paying her first visit to the Irish Republic.

Decades of dogma were discarded in one extraordinary day, presenting all sides with a whole new political architecture and challenging Northern Ireland politicians to make a success of the ingenious new arrangements.

They made a start on doing so - the new coalition executive holding its inaugural meeting in Stormont's Room 21 in what was described as a friendly and co-operative spirit. David Trimble, chief minister and Unionism's principal moderniser, was first to stride in, matter of factly businesslike for the cameras.

Martin McGuinness, of Sinn Fein, the Education Minister, followed him in, saying: "How're you doin'?" in friendly fashion to the woman who held open the door. On his lapel he wore the republican green ribbon, which demands the speedy release of IRA prisoners.

The two men, with the deputy chief minister, Seamus Mallon, and others settled themselves at the Camelot-style round table from which the new cabinet is to govern Northern Ireland.

It all looked friendly and good-humoured, though Sam Foster, the new Unionist Environment Minister who pulled friends from the rubble after the 1987 IRA bomb in Enniskillen, tended to immerse himself in his papers rather than engage in banter.

But this was a day for getting down to business rather than indulging in recrimination, and the new Cabinet determinedly looked to the future rather than to the past.

When the chief minister noticed that Mr McGuinness had mistakenly sat in the seat reserved for the Unionist Michael McGimpsey, he called out "Hello, Mr McGimpsey," producing some slightly over-loud laughter. Then the other Sinn Fein minister, Bairbre de Brun, entered, her sober outfit enlivened by a suitably green scarf.

Mr McGuinness first helped himself to water but later accepted a cup of coffee - milk but no sugar - ending up with a glass of water on the one hand and a coffee on the other. Everyone smiled for the cameras, then the door closed and they got down to business.

But even if it was a new dawn not everyone wished to celebrate it or even admit it. Two empty seats at the table signified the absence of the Rev Ian Paisley's cabinet nominees, Peter Robinson and Nigel Dodds. They will handle regional development and housing in the new administration, but they will do so on a semi-detached basis, having said they will be ministers but will not sit down with Sinn Fein. This stance reflects the state of mind of a substantial section of the Protestant community, which approves of some, but not all, of the new order.

Reams of rhetoric accumulated in Belfast, Dublin and London as the day wore on, though the dramatic reality meant that for once it did not seem exaggerated or unjustified. Tony Blair declared: "Thousands of lives have been lost, millions have suffered from inequality and injustice. Every generation has suffered. Today, at least we can say that we have the beginnings of a new dispensation with hope in place of pain, confidence in place of fear."

In Dublin, Bertie Ahern said: "The past six days have seen historic developments for the people of Ireland, north and south. Hopefully politicians north and south can now make all the new institutions work. They will have the opportunity."

Mr Mallon added: "This is the birth of something absolutely imaginative, creative and new. We are beginning a new era and have ended an era of great difficulty and great suffering. I hope that in years to come we will all be able to look back on this day and say that this was when the new era began."

Even as the historic cabinet meeting was taking place, however, Mr Paisley was stating his traditional position with as much bad grace as he could muster. "This is not a daybreak, not a new dawn," he declared. "This is a new night and one does not know what the midnight will be.

"We have now spokesmen of the armed IRA in government. They are there to forward one interest only: to break the link between this part of the United Kingdom and the rest of the United Kingdom." He went on to claim that Ms de Brun, as Health Minister, was "there to remove as many Protestant employees and Unionist employees as she can and get the republicans into jobs".

His attitude was a reminder, if it were needed, that the new dispensation will be tested daily by many of the old problems. Among the difficulties that have not gone away are the vexed questions of what to do about the Royal Ulster Constabulary and policing, what will happen on decommissioning, and how to solve Drumcree and the other marching issues.

The high "peace-line" walls still dominate the landscape in the backstreets of Belfast, and many minds still have walls in them too. This may be the beginning of peace, but reconciliation is a long way away, and friendship between the two traditions is still further off.

Yesterday was a giant step by any standards, however, and one that many thought they would never see. The peace process has been a harrowing journey, prey to pessimism and full of anxiety and uncertainty, but the events at Stormont amounted to a breathtaking breakthrough.

The new arrangements for government are simultaneously mundane and amazing: this new Cabinet is to meet each Tuesday at 11am. Unionists and republicans have for years grappled with their history, but this will be something different. Each Tuesday, they are going to grapple with it together, in the beginnings of amity rather than enmity.