Heath, Wilson, Callaghan, Thatcher, Major, Blair, Brown, Cameron, Cosgrave, Lynch, Haughey, FitzGerald, Reynolds, Bruton, Ahern, Cowen, Fitt, Hume, Durkan, Ritchie, McDonnell, Paisley, Robinson, Faulkner, West, Molyneaux, Trimble, Empey, Elliott, Nixon, Ford, Carter, Reagan, Bush, Clinton and Bush.
That's the list of prime ministers, Taoisigh, local party leaders and US presidents who have come and gone since Gerry Adams was released from internment in June 1972 to represent the IRA in secret talks with the British government. He has been president of Sinn Féin since 1983.
He's like Methuselah and the 'dreary steeples of Fermanagh and Tyrone' rolled into one.
For about 45 years - and he's now 67- he has been the key strategist and spokesman for the Provisionals and Sinn Féin. It no longer matters if he was/is a member of the IRA, because he is clearly trusted by them and the membership question hasn't stopped him being elected to Westminster, the assembly and the Dail. And whatever some of the younger generation within Sinn Féin may think about him - particularly those from the Republic, who have no links with the IRA - we will never find out, because there seems to be no one willing to brief against him or put serious pressure on him to stand down.
In an interview for the Irish News last week he told Deaglán de Bréadún: "I've no plans to retire." Yet a few days later Thomas McNulty, chair of Sinn Féin's Cavan cumann, claimed that Adams was damaging the party's electoral prospects in the south.
Then on Tuesday, Eoin Ó Broin, Sinn Fein's housing spokesman in the Republic, said that he thought that it was quite possible that Adams would step down within the next five years. Adams denied it immediately: "No, not at all. He must know something that I don't."
While this sort of stuff irritates Adams it does raise the very legitimate question of why he hangs on. Is he still essential to Sinn Féin? Or, putting it more bluntly, would the party be worse off without him? He clearly thinks so, which is why he left Martin McGuinness to front the show in the assembly (although that has also something to do with the psychological fact that he would never, ever be 'deputy' to any unionist) and headed to Louth.
As we have seen, though, he has been prepared to overrule the assembly party (particularly in March 2015 when he forced McGuinness to backtrack on some of the Haass commitments); which may have cost them votes and seats at the last Stormont election. But set against that is useful evidence of Sinn Féin's electoral improvement in the south since 2010.
Whether the party would do better in the south under new leadership is something that can only be gauged if he steps down, something which he seems disinclined to do. They did ok in the last election - although not as well as they had hoped - but recent polls suggest further slippage from them and a drift towards Fianna Fail. And with another election not far away it remains a possibility that Sinn Féin could lose some seats.
Clinging to office suggests unfinished business. It also suggests that he doesn't think there is anyone at the moment, north or south, who would do a better job. I wonder if he does have one final goal in mind? There was clearly a time when he believed that Northern Ireland was on the cusp of being absorbed into a united Ireland, or why else would he have bought into the Good Friday Agreement? But as that dream faded he switched his attention from here and focused on pushing Sinn Féin into government in the Dail. That hasn't happened, either.
His hopes will have risen as a consequence of the Brexit result, as well as the likelihood of another general election in the south: and he may also believe that recent Irish unity comments from Micheal Martin and Enda Kenny are pushing events in his favour.
But, and it's an enormously big but, it requires just about every political/electoral/economic/circumstances card to fall in his favour; the most important of which is overwhelming evidence of a shift of opinion in Northern Ireland towards Irish unity as the price to be paid for remaining in the EU. Not impossible, I grant you, but still extremely unlikely.
It won't be long until Adams will be able to add Kenny and Obama to the list of those he has seen come and go. Ironically, the only person in my lifetime who has hung on as long - longer, in fact - in British/Irish politics is the Queen.
