Van Miert was born in 1942, in Oud-Turnhout, in the region of Antwerp province known as the Kempen. The eldest of nine children of a poor Catholic family, he quit school at 14 and worked on the family farm, then became an electrician's apprentice before finally resuming his education. At 20, he went to the University of Ghent, where he studied international relations. His thesis, with uncanny prescience, was on the supranational role of the European Commission.

With this background, he ought to have gone on to Leuven and adopted the politics of the CVP (now CD&V). But something, perhaps his experience of seeing people work punishingly hard for little return, turned him towards the socialist party - at the time a single party straddling both sides of the language divide. By his own account, he lost his faith when he saw the hypocrisy of the people who "tried to saddle us with all sorts of principles which they themselves did not live by."

Van Miert was a contemporary of Willy Claes and Louis Tobback, themselves the product of poor backgrounds, and together these so-called Red Lions helped bring about a split in the socialist party. Van Miert would go on to lead the Flemish wing for 12 years.

It was a great time for the socialists (SP), culminating in the 28% score obtained in the federal elections of 1984 - better than anything before or since. Under Van Miert, it cut some of its ties to the unions and began to turn its attention outwards. Van Miert became a committed European, sitting in the European Parliament from 1979 to 1985.

In the 1980s, Van Miert was a prominent critic of the decision to site cruise missiles on Belgian soil, leading to fierce protests, which at one point brought 400,000 people onto the streets of Brussels. In 1988, however, he changed his position on the missiles (though he never admitted doing so) to allow the SP to form part of the new government coalition under prime minister Wilfried Martens.

The following year, Van Miert became a member of the European Commission under Jacques Delors, where he was responsible for transport. There, his quiet determination and command of his portfolio led to him being entrusted in 1993 with competition policy. The committed socialist was now the man corporate Europe feared the most. Under his defiant leadership, the commission took on companies like Boeing, Coca-Cola, Alitalia, Volkswagen and WorldCom.

The end came in 1999, when the Santer commission, the third in which Van Miert had served, was brought down by the shady affairs of French commissioner Edith Cresson. The European Parliament voted the whole commission out, and Van Miert, who was never under any suspicion, was part of the collective departure.

He had brushed up against corruption before. In the last year of his chairmanship of the party, in 1988, the defence ministry under Walloon socialist Guy Coëme took kickbacks in the purchase of a fleet of helicopters from the Italian manufacturer Agusta. Some of the money made its way to the Flemish party. Frank Vandenbroucke, who succeeded Van Miert to the chairmanship, resigned as foreign minister, and Willy Claes, Van Miert's old mentor, resigned as secretary-general of Nato.

Van Miert himself was above suspicion, but the position of party national secretary Carla Galle, who was by then his partner, was less clear. Van Miert defended her, and split with his old comrades from the days of the Red Lions. The breach lasted years, until Steve Stevaert as incoming party chairman in 2003 reached out to him.

"Yesterday I lost a friend and a comrade," Stevaert commented when the news of Van Miert's death broke. Stevaert was only one of the many political figures from all over the spectrum who reacted along the same lines. Van Miert was "a personal friend," said prime minister Herman Van Rompuy. He was "a good, personal friend," said former prime minister Wilfried Martens. For EU Commissioner Louis Michel, he was "a true pillar of European construction." Guy Verhofstadt found him "a visionary."

In his last days, other than several lucrative company directorships, he was a gardener. His garden was his paradise, with 200 fruit trees, including many heirloom varieties, and an equally rich vegetable garden with dozens of strains of tomatoes and squash.

Van Miert, who as a minister of state was entitled to a state funeral, was buried at the weekend in the presence of only a small group of family and close friends.