IT was the best thing to happen to Offaly since Seamus Darby's late winning goal in the 1982 All-Ireland football final.
Dozens of the "Brian Brigade" had travelled up from Offaly on a mini-bus to celebrate the culmination of almost 25 years of canvassing.
The contingent included his two brothers, Barry -- who is a councillor in Offaly -- and Christopher, who recently made a €100,000 tax settlement with the Revenue.
And they crowded round the Tanaiste after his debut as leader-in-waiting with the same sort of dazed disbelief the Offaly supporters experienced on that famous All-Ireland day.
Long-term canvasser Kathleen Bracken said it was "absolutely" a better feeling than the All-Ireland final victory over Kerry.
"I'm proud to be here today -- we didn't think it would come so soon but we knew it was coming," she said.
Although they had been instructed by Mr Cowen to keep the celebrations low-key, they couldn't resist cheering him when he spoke about his relationship with the people of his native county.
"What I say to them is I hope that will continue to keep my feet on the ground and they continue to support me," he said.
The most important guest was Mr Cowen's wife, Mary, who runs his constituency office in Laois-Offaly. She was accompanied by Sinead (16), the eldest of their two daughters, but politely declined all requests for interviews.
Mr Cowen specifically referred to his family, including his youngest daughter Maedbh (9), saying that it was a proud moment for them.
"It's also a proud day for my mother May, my brothers, and members of my wider family," he said. However, Mr Cowen once again laid down a marker by saying that it was important that the privacy of his family be respected. His mother is expected to be in the Dail on May 7 for his official unveiling as Taoiseach.
But Barry Cowen revealed that the accession also brought back memories of his father, Ber, who represented the constituency in Fianna Fail until his sudden death at the age of 52.
"It's very poignant for us -- we remember our dad and we remember our grandad, and our late uncle, Fr Andrew, who was very involved with us as well," he told RTE.
Andrew Dignam, a member of the Ber Cowen cumman in Clara, said that Ber would have been proud to see his son becoming Taoiseach. "It was a very sad time back then when Ber was lost to us because he was an able servant to the town.
"But Brian has more than proven himself and it's fantastic for the Fianna Fail organisation in Laois-Offaly," he said.
He was one of the election workers who was told by Mr Cowen last May to "get every vote" in the constituency and the end result was a personal tally of more than 19,000 -- the highest in the whole country.
"He's a true Fianna Fail man and he wants to ensure that the vote is managed properly. We'll be going for four seats (in Laois-Offaly) in the next election," said Mr Dignam.
Another member of the Ber Cowen cumann, Tom O'Keeffe from Clara, remembered how he had heard Mr Cowen getting into a political row at the age of just six. At the time he had been travelling to a football match in a car whose driver was praising Fine Gael.
"Brian said, 'There is no good in Fine Gael, any good that is in politics is in Fianna Fail'," recalled Mr O'Keeffe, who agreed that the Taoiseach-in-waiting had stuck consistently to this line ever since.
He also said that Mr Cowen had played as a wing forward and corner forward with Clara and with the Offaly football team in 1980 and 1981.
"He was a good and enthusiastic footballer. He was also secretary of the club and he's still our president," he said.
Among the dozens of Fianna Fail TDs in attendance at the Royal College of Physicians in Dublin was Donegal North East representative Niall Blaney, who said he was "ecstatic" about Mr Cowen's rise to power. When difficulties arose about bringing him and the Blaney organisation back into Fianna Fail before the general election, Mr Cowen played a "vital role" in sorting them out, he said.