On any other day the fact that the President, Mrs McAleese, attends lunch at Queen Elizabeth's invitation in Buckingham Palace would be deeply significant. When that day coincides with the first full day of devolution in Northern Ireland for some 25 years, it can rightly be described as a momentous event.
Phrases such as "spirited optimism" were, for once, not out of place. A few hours after Articles 2 and 3 of the Constitution were abolished, the President, wearing a pale blue two-piece dress and coat, arrived at the West Terrace of Buckingham Palace. She was accompanied by her husband, Dr Martin McAleese, the Minister for Foreign Affairs, Mr Andrews, and his wife, Annette, who had flown in from Dublin after the official devolution ceremonies.
At precisely 1.10 p.m. they were greeted by Queen Elizabeth's youngest son, the Earl of Wessex. Prince Edward was representing the Duke of Edinburgh, who had a prior engagement. A small contingent of the Scots Guards, the duty guards at Buckingham Palace, stood to attention and gave a royal salute, and the President's party entered the palace.
The private lunch took place in the palace's 1844 Room, which commemorates the first state visit by Tsar Nicholas I of Russia in that year. It is understood to be one of the rooms favoured by the queen over the grander palace dining hall for private gatherings.
Among the 14 guests were the secretary-general to the government, Mr Martin Murray; the Irish Ambassador to Britain, Mr Edward Barrington, and his wife, Clare; the British ambassador to Ireland, Mr Ivor Roberts, and at least three ladies-in-waiting.
After a 75-minute meeting Queen Elizabeth escorted the President from the palace, deep in conversation about the "big adventure" ahead for the people and politicians of Northern Ireland.
The President's five-day visit to Scotland and England this week is not a state visit, but Buckingham Palace officials were keen to point out that the timing of the lunch was happy, bearing in mind events in Belfast. There is now increased speculation that Queen Elizabeth may be invited to make a state visit, and the President dealt skillfully with the question when she was asked after if such a visit could take place next year.
"Funnily enough, it wasn't a matter we discussed at all today at lunch", Mrs McAleese told journalists assembled at the Dorchester Hotel in London.
But she carefully added "I certainly look forward to hosting her at some stage in the future. The events of today make that all the easier, but as to the particular year, that's a matter for the two governments to agree between them." Mrs McAleese spoke warmly about Queen Elizabeth's reaction to devolution and the events taking place in Northern Ireland.
"She was very excited about them. . .and very, very grateful that we should meet on a day like this when such historic events were unfolding all around us. Both of us feel very deeply grateful, very privileged to be part of it."
Queen Elizabeth supported devolution in Northern Ireland "very clearly, without the remotest shadow of a doubt", Mrs McAleese said. "We were very grateful to the politicians, they have shown leadership.
"She was very conscious of this today, to remind people that at the end of the day, every single person, not just in Northern Ireland but on these two islands, has a role to play in building up a new way of looking at each other and importantly, getting rid of old ways of looking at each other."