The encounter initially looked like it would heighten the impression that Micheál Martin is slowly preparing for his own changing of the guard with the outcome of Friday’s by-elections likely to provide their own confirmation of that position.
But that was before the bombshell news that Martin had asked the Pope to intervene with the religious orders in Ireland to provide hundreds of millions of euro in compensation for the victims of clerical abuse.
It was a stunning manoeuvre as he spoke with the American head of the Roman Catholic Church.
It was almost as radical as Enda Kenny’s decision to close the Irish embassy to the Holy See for a time in 2011.
The decision followed an abuse report that highlighted a Vatican policy of taking no action on confirmed abuse reports, moving the perpetrators to new areas instead.
The media had not expected the Taoiseach’s revelation, which came after the usual review of world events, particularly the Middle East, that Martin said was discussed in the Pope’s private library in the Apostolic Palace.
It was a question about the intractable non-payment by religious orders that unlocked Martin’s disclosures about a direct demand that the Pope himself should make his views known to religious orders at home.
Martin also said he had discussed the trauma of victims with the Pope, who had answered his request “in the affirmative”.
Nothing so dramatic had seemed on the cards when Martin’s limousine swept into the cobbled courtyard of San Damasso, off St Peter’s Square, at 9.45am.
His was a meeting between visits from the presidents of the respective parliaments of Bulgaria and North Macedonia, but was diplomatically the most important, involving the honour guard of the Swiss pikemen.
The Taoiseach was greeted by Cardinal Petar Rajic of Croatia, who is the Prefect of the Papal Household in the Apostolic Palace which fronts on to the courtyard, with the papal apartments on its second floor.
It is from a shuttered window there that the Pope delivers his annual Urbi et Orbi message to the world every Christmas.
As Martin arrived, tourists were already winding their way through snaking queues in St Peter’s Square, hoping to enter the imposing basilica itself. In the heart of the square stands a statue of St Peter grasping the keys of the kingdom of heaven, a reminder that the Pope is the Vicar of Christ on Earth.
The Taoiseach equally grasps the keys of political power, even as there are those who would seek to loosen them from his grasp.
For Mary Lou McDonald, Ireland’s would-be first female head of government, the outcome of the poll in Dublin Central, a constituency vastly bigger in size and population than the Vatican, is a key consideration at home.
Martin visited the Irish College in Rome, where he viewed a monument containing the heart of The Liberator, Daniel O’Connell, whose body is buried in Glasnevin Cemetery.
When O’Connell was on his deathbed in Genoa, intending to make a pilgrimage to the Eternal City, he pronounced that his soul would go to God, but his heart should go to Rome and his body be repatriated.
The marble monument was paid for by the carriage operator Charles Bianconi and erected in 1854.
It also contains a relief of O’Connell refusing the oath in the House of Commons in 1829 because of its sectarian wording – one means by which he won Catholic emancipation later that same year.