He has been famously portrayed as a bore, a man whose habits were so regular that housewives could set their watches by his legendary afternoon walk.

But according to three new biographies, the celebrated German philosopher Immanuel Kant was not such a dry stick after all. Far from being a dour Prussian ascetic, the great metaphysician was a partygoer. He enjoyed drinking wine, playing billiards and wearing fine, colourful clothes.

He had a sense of humour, and there were women in his life, although he never married. On occasion, Kant drank so much red wine he was unable to find his way home, the books claim.

The biographies - which shed fresh light on the party-loving behaviour of the young Kant before his fame - have appeared in Germany ahead of the 200th anniversary of his death today.

They also coincide with a visit by Germany's foreign minister, Joschka Fischer, to Kaliningrad - the Russian Baltic port where Kant spent all his life when it was Königsberg, in what was then East Prussia.

Mr Fischer set off from Berlin yesterday and took several German philosophers with him. He is expected to lead the Kant anniversary celebrations today by laying a wreath on the philosopher's memorial and will open a German consulate in the city.

"Kant is traditionally portrayed as someone who led a mechanical life," Manfred Kühn, Kant's leading biographer, told the Guardian last night.

"This is of course the picture of the old Kant, the Kant who had written all his major works. But if you look at the young Kant you find an entirely different picture. He was a very social type who often went to parties and sometimes drank too much. At times Kant could not find the street where he lived because he was so inebriated.

"He had a sense of humour. Not a German sense of humour where you have to spell out that you are telling a joke but a dry Anglo-Saxon wit."

According to Kühn, whose acclaimed biography of the philosopher has just been published in Germany, Kant also had "amorous interests" in two women - though there is no evidence these were consummated.

It was only at the age of 57, after Kant had published his most famous work, his Critique of Pure Reason, that he was in a position to support a wife. "By this time it was too late," Kühn said.

Last night Professor Volker Gerhardt - a leading member of Germany's Kant Society, who travelled to Kaliningrad for today's celebrations - said he endorsed Kühn's view of Kant.

Kant socialised extensively with Joseph Green, an English merchant who taught him about British culture, Prof Gerhardt said. His great achievement was to develop a philosophical system that separated morality from religion, as well as a liberal political theory which anticipated both the UN and modern human rights.

Two other intellectual biographies of the philosopher have just been published in Germany - Kant's World by Manfred Geier and Immanuel Kant by Steffen Dietzsch. The three books are the first Kant biographies for half a century.