Even in this extraordinary general election, the result in Wales almost defies belief. Recall that the first Welsh two polls of the campaign put the Conservatives on historically high levels of support, and apparently on course to transform electoral politics in Wales by capturing a long list of seats from Labour. Subsequent polls had shown Welsh Labour fighting back very strongly, and our final pre-election Welsh Political Barometer had suggested that Labour might even re-capture the two seats they had lost to the Welsh Tories in 2015. But few anticipated a Labour performance as strong as the one we actually got.

Let us put some historical perspective on this. Yes, Labour have long dominated elections in Wales – this was the 26th successive general election where they have won the most votes and seats. But given the difficult start to the election who could ever have expected that Welsh Labour would gain their highest vote share since the very high watermark of the first Blair landslide in 1997? Or that the party would not only regain the two seats narrowly lost in 2015 but also add to this Cardiff North?

Quite how this Labour success is interpreted might be crucial to the future of the party in Wales. Was this down to Welsh Labour – a campaign focussed around First Minister Carwyn Jones with Jeremy Corbyn was largely excised from party campaigning materials? Or is this interpreted simply as part of a much better result for Labour across Britain than almost everyone had anticipated – and for which Jeremy Corbyn’s active and increasingly impressive campaigning must surely be given plenty of credit?

For the Welsh Conservatives, this has been a desperately disappointing election. Far from producing an historic breakthrough for them, election 2017 has seen the party fall back to its 2010 level of eight seats. We should note that the Conservative vote share in Wales is its highest since 1935/before World War I: the problem has not been falling Conservative support so much as the extraordinary campaigning resilience of Labour. But the Welsh Tories have hardly helped themselves. Assembly leader Andrew RT Davies produced a performance in the first Welsh Leaders’ debate that attracted open derision from the audience, while the second such debate saw a farcical dispute about who should even represent the party.

Plaid Cymru made one gain in this election. The party’s young rising star, Ben Lake, finally extinguished the long Welsh Liberal tradition by gaining Ceredigion. Plaid also held their existing three seats – though only very narrowly in the case of Arfon. But elsewhere their performances were mostly dreadful. Plaid won their lowest vote share since 1997, lost by embarrassingly wide margins in some seats – Like Rhondda and Blaenau Gwent – where they had talked up their chances, and the future of party leader Leanne Wood must now be in serious question.

This election challenges many of the things that psephologists have long held to be true. Plentiful evidence across many electoral contexts has documented that election campaigns rarely produce much aggregate change in voting intentions. But that was hardly true in 2017. Scholars have also believed strongly, with good reason, that divided parties rarely prosper. Yet despite their UK party leader being openly rejected by a very large proportion of his own MPs, and in the face of enormous hostility from much of the press, Labour have produced an election result that appeared impossible only a month before polling day. And in Wales that result has been the most impressive of all.