Famed for the annual royal rowing regatta, ladies in large hats and Pimm's, Henley marked a new low for Labour under Gordon Brown when the party was beaten into a humiliating fifth place in the by-election.
Gordon Brown tried to brush off the result in the staunchly Conservative seat, saying "by-elections come and by-elections go". But it was the first time since the Second World War that Labour has come fifth in a by-election and it caused panic in the ranks.
Labour also lost its deposit for the first time since the Cheadle by-election in July 2005. But more worryingly for Mr Brown, Labour was beaten by the Greens and the BNP.
Labour MPs warned that Mr Brown would have to change direction or face a challenge for the leadership. Alan Simpson, a member of the left-wing Campaign Group, said: "He's got until the end of the year. If he hasn't changed direction, it's the end of the pier.
"Every time we think we have hit rock bottom, the party manages to find a lower level. Something has got to change if we are going to stop the descent turning into freefall."
The Health minister, Ben Bradshaw, admitted it had been a "terrible result" for Labour on the first anniversary of Mr Brown's term as Prime Minister.
But he said: "We've got the credit crunch, we have a doubling in oil prices, we have had food prices rise by 40 per cent since spring. That's a difficult economic backdrop. I don't believe [Mr Brown] is personally unpopular."
The by-election was caused by the decision of Boris Johnson, the sitting MP, to quit after becoming Mayor of London. Henley had been held by Michael Heseltine and there were fears the poll could backfire on the Tories after a stunning victory over Labour in Crewe and Nantwich.
David Cameron, the Tory leader, ordered his entire press headquarters to move to Henley for the final day of canvassing. The Tory victor, John Howell, a local councillor, won by a comfortable margin of 10,116.
Mr Cameron, hosting a Shadow Cabinet "away-day", said it was the first time for years that there had been a by-election contest between the Liberal Democrats and Conservatives where there had been swing to the Tories.