By Brian Rowan
BBC Northern Ireland security editor
It was the day the Army started to say goodbye after a decades-long operation in support of the police in Northern Ireland.
The past few days have been truly remarkable - with words and actions pointing to some sort of endgame.
The RIR's NI-based battalions are to be disbanded
We knew that when the IRA ordered an end to its armed campaign, that we would see the security landscape transformed and that is what is happening.
Operation Banner - how the Army has described its back-up role first to the Royal Ulster Constabulary and then to the Police Service of Northern Ireland - will end on 1 August 2007.
It will be 35-years-old when it is brought to a close - the longest military operation in the history of the British Army.
Between now and then, watchtowers and bases will be demolished, troop numbers reduced to 5,000 and the Northern Ireland based battalions of the Royal Irish Regiment - which grew out of the Ulster Defence Regiment - will be stood down.
What will be left of the Army in Northern Ireland in two years time will be a peace time garrison.
The remaining soldiers will not be seen on the streets but will be deployed elsewhere when needed.
Republicans will view this as "military Brits out" - that is its real significance.
NI security editor Brian Rowan talked to Colonel Mark Campbell
And, in the new situation that is developing, Sinn Fein's Martin McGuinness has spoken of the "soldiers" of the IRA and the British Army beginning to trust each other.
These may not be the words that the Army's commanders would choose, but in their actions they are telling us that they believe that the republican "war" is over.
Colonel Mark Campbell of the Royal Irish Regiment said as much when I asked him: "Did he trust the word of the IRA?"
"Well, there is a verification process in place of course," he said.
"They will have to deliver on their words. But our view is that that is most likely to occur, yes."
The colonel stood solidly at his wicket as I bowled towards him that his soldiers had been thrown to the "political wolves" and that the end of the home-based battalions of the Royal Irish Regiment had been delivered on demand from Sinn Fein.
Given what was evolving, he said he believed the security response was "practical" - and the specific decision on his regiment was "decent and honourable".
He told me these were Army decisions based on security assessments which had not been influenced by politics.
Unionists won't believe that, and you could feel the political earthquake beneath your feet when the announcement came at noon on Monday 1 August.
The IRA's statement has long been anticipated
But we are seeing that they have no influence on this process of security decision making.
Within hours of Monday's announcement, more of the military watchtowers were being pulled down in south Armagh and work has begun to remove the Army's monitoring equipment from Divis Tower in the constituency of the Sinn Fein President Gerry Adams.
There is, of course, unfinished business.
Ian Paisley's Democratic Unionist Party will have a big say in the politics of re-building the power-sharing executive at Stormont.
Then there is the issue of how you bring Sinn Fein to the position of endorsing the Police Service of Northern Ireland and joining the Policing Board in Northern Ireland. And there is decommissioning.
It could be weeks before we hear from General de Chastelain that the job of putting the IRA's arms beyond use has been completed.
He is back in Canada and his colleague Andrew Sens is in the United States.
I am told there will be "no running commentary" on decommissioning.
The general will report when the job is done, the new church witnesses will speak and the IRA's 'P O'Neill' might well pen his last words of this "war".
The past few days have given us the stuff of history - words and actions that point towards a better peace than the one we have had so far.
But there is another question: Are the loyalist paramilitaries watching and listening?
Because, in the here and now of Northern Ireland, it is their guns that are loudest.