Micheal Martin, who made his first visit as Taoiseach to Northern Ireland on Thursday, remains something of an unknown quantity to most people here, despite being around the Irish political scene far longer than his predecessor.
Leo Varadkar only became a TD in 2007. By that point, Martin had been in the Dail for 18 years and had already served as a Cabinet minister in three different departments.
It's a measure of how little people on both sides of the border still know about each other that he remains such a mystery, despite one of those previous posts being Minister for Foreign Affairs which meant that he was constantly in and out of Belfast.
As it happens, people in Northern Ireland didn't get much of a chance to find out about him on Thursday, either. The Corkman made a flying visit to Stormont, gave a Press conference that was full of the usual bland soundbites, then went home.
His face is now slightly more familiar, but who is Micheal Martin really? And what difference will he make as Taoiseach?
The first thing to say is that coming north probably came as something of a relief in the present circumstances. He's had a rough ride in his first few weeks in the job and has already been forced to sack one colleague, Barry Cowen, when the former, brief-serving Agriculture Minister refused to give further statements to the Dail about the circumstances in which he was charged with drink-driving in 2016, when he still held a provisional licence.
Martin was already facing pressure from within party ranks over his appointments to the Cabinet. Fianna Fail has been out of office for nine years, an unprecedented period for the party, which held office for more than 60 of the 79 years before the disastrous 2011 election.
There were many in the party with expectations that they would be rewarded with plum jobs, but it simply wasn't possible to satisfy them all, considering that Fianna Fail is now in a three-way coalition with Fine Gael and the Greens.
Resentment was inevitable and sacking the younger brother of an ex-Taoiseach doesn't come without political cost.
There are already rumblings of discontent in pockets of the party at how Martin has handled his first few weeks as Taoiseach. The malcontents probably won't make a move against him yet, but he won't be foolish enough to be complacent.
He's already had one near-miss. February's election, which saw Sinn Fein come out as marginally the largest party in terms of vote share and only one seat behind Fianna Fail when it came to TDs in the Dail, led to months of tense negotiations.
Had talks on a Programme for Government fallen apart, it's unlikely that Fianna Fail would have headed into another election with Martin at the helm.
He must know he was blessed to avoid that fate, but the divisions inside the party still harbour the potential to cause him serious problems.
Micheal Martin wouldn't have wanted to sack Barry Cowen, but that he put the government's collective well-being above personal loyalty is a pointer to his character.
He may sometimes be guilty of a lack of pizzazz, or imagination, but he takes his public service responsibilities seriously and that caution will probably be to Northern Ireland's benefit over the next few years. His instinct is always to steady, rather than rock, the boat.
More than any other senior politician in Ireland, he's also given thought to what any future united Ireland would have to look like in order to win the loyalty of unionists and he's managed to do that in a way which is authentically inclusive and non-threatening.
When many nationalists talk about Irish unity, they do so with an implied threat that it's coming anyway, so unionists had better get used to the idea. Micheal Martin has never taken that tone.
The idea of a tolerant and pluralistic Republic is not merely a slogan to him, but something he regards as his duty to promote. His meetings with the various parties on Thursday took place in the same spirit.
Ulster Unionist leader Steve Aiken said afterwards that it was an opportunity to "reset relations". First Minister Arlene Foster talked about showing "mutual respect for both jurisdictions and an understanding of each other's differences".
That's what he brings to the table in what is still a fractious atmosphere at Stormont. His public remarks while in Belfast may have been anodyne, with much vague talk of north/south and east/west co-operation, but he made sure to reaffirm his opposition to a divisive border poll.
This refusal to wrap himself in the green flag is one of the reasons why Micheal Martin is genuinely despised by Sinn Fein.
Mary Lou McDonald can get stuck in verbally to Leo Varadkar, but the republican leader can probably imagine herself working alongside the current leadership of Fine Gael much more than she can Micheal Martin, despite the superficial resemblances between their two parties with republicanism in their blood.
Some in Fianna Fail may welcome the chance to kiss and make up with Sinn Fein, from whom they split in 1926 over the Anglo-Irish Treaty, but Micheal Martin has never been one of them and Sinn Fein knows it. When Mary Lou talks about the new Taoiseach, it is with undiluted enmity.
For the past few years, her party and his have jostled as rivals to lead the Opposition. Fianna Fail had the numbers in the last Dail to take on that role officially, but providing support to the Fine Gael minority government as part of a Confidence and Supply agreement undermined some of their claim to provide an alternative.
Martin's sense of responsibility meant that he stuck with the agreement anyway as the EU and United Kingdom fumbled towards a Brexit deal, but his party undoubtedly suffered in the polls as a result.
Many were itching to pull the plug on the government and force an election. It's arguable they might have fared better had they done so earlier.
Sinn Fein was better able to present itself as an alternative government, only to miscalculate badly when the time came in February's election by not running enough candidates to capitalise on the mood for change, which was undoubtedly there, even if it wasn't as strong as many commentators have since pretended.
(The new government represents 52% of the voters who went to the polls in February. Sinn Fein got just 24.5%, which, unless maths has changed, is very far from being a majority).
Sinn Fein was exultant at the result in February, but stung, too, by an inability to capitalise on the result by translating it into power.
The long delay before the other parties could put together a working majority helped them to regroup. They were shut out of talks, or shut themselves out, depending what view one chooses to take of it, and that further helped cement their posture as outsiders.
They play that game to perfection, even managing to talk and act like an Opposition when in government in Northern Ireland.
The electorate down south has no direct experience of Sinn Fein being in power and younger voters, in particular, don't seem all that curious to look at what the party does when it actually holds office, choosing instead to buy the fantasy about Westminster being to blame for everything that's wrong in Northern Ireland.
Now that Fianna Fail has gone into government and will, in due course, be judged accordingly, Sinn Fein has that space in Opposition to themselves and can make wild promises to its heart's content.
They're the only real alternative now, with only a weakened Labour Party, a smattering of far-Left agitators and some Independents and others alongside them on Opposition benches. That gives them a ready-made platform for the next four years, or however long the new government lasts.
It won't be easy to translate that into future support, because, after the coronavirus crisis, many voters may welcome some dull stability for a while as the country gets tentatively back on its feet, meaning there will be no desire for disruption and, reassuringly for unionists, certainly none for a border poll.
But there are still huge social and economic challenges facing Dublin that could play right into Sinn Fein's hands.
A post-Covid-19 economic slump would be a gift to Left-wing populists and, even if that disaster is avoided, the two issues which helped the party among disaffected voters in February - housing and health - are far from solved.
Fianna Fail has admirably taken on the mantle of those two departments in the new government, while Fine Gael and the Greens took the easier options.
It means that Fianna Fail and Sinn Fein will be going head-to-head for the next few years on those key issues.
Mary Lou (below) has promised that Sinn Fein will provide "one hell of an Opposition" and the fact they now have the considerable resources available to the official Opposition to use as weapons against the new government will give them added clout. A compliant Dublin media will also be to their advantage.
The ball is still the new government's to drop. There's no reason why, with discipline, it shouldn't go the full term and maybe beyond, not least because Sinn Fein faces an additional hurdle, which is how to form a future government from the ragbag of parties who sit alongside them on the Opposition benches.
The numbers just aren't there and Sinn Fein doesn't exactly make friends and alliances easily. They like to be top dog, rather than build coalitions of equals.
Being the largest party isn't enough; they need to bring in a sufficient number of Left-leaning TDs at the next election to form a government, which is hard to do when you're fishing for votes in the same pool of support.
But Sinn Fein will not be caught napping again, as they were in February. Micheal Martin knows that, which is why his instinct will be to make friends as a bulwark against Sinn Fein's advance.
That should suit Northern Ireland over the next few years, when calm heads will be needed more than ever.
In the time before the top job reverts to Leo Varadkar in their weird "rotating Taoiseach" arrangement, Micheal Martin may even find being in Belfast a welcome distraction from party infighting in Dublin.