Jacques Delors, a former head of the EU Commission and key figure in the creation of the euro currency, has died, his daughter Martine Aubry told AFP on Wednesday.
Delors, who was 98, died in his sleep in his Paris home on Wednesday, she said.
Delors, a Socialist, had a high-profile political career in France, where he served as finance minister under president Francois Mitterrand from 1981 to 1984.
But he declined to run for president in 1995 despite being overwhelmingly ahead in the polls, a decision he put down to "a desire for independence that was too great".
"I have no regrets," he said about that decision later. "But I'm not saying I was right."
He headed up the European Commission from 1985 to 1995, a decade that saw major steps in the bloc's integration.
These included the completion of the common market, the Schengen accords for travel, the Erasmus programme for student exchanges and the creation of the bloc's single currency, the euro.
His drive for increased integration met with resistance in some member countries, especially Britain under prime minister Margaret Thatcher.
"Up Yours Delors" read a famous 1990 front-page headline in The Sun newspaper which voiced its concerns about a single currency and increased powers for the European Parliament.
Alastair Campbell, a former campaign director for ex-British prime minister Tony Blair, said on X, formerly Twitter, that his "favourite Delors-ism" had been: "Don't be a pessimist. Or an optimist. Be an activist."
"RIP Jacques Delors. Quite a life," Campbell said.
Delors founded think tanks with the aim of furthering European federalism even after he left office, and in recent years warned of the dangers of populism in Europe, also calling for "audacity" in dealing with the Brexit fallout.
He also urged more solidarity among EU members during the coronavirus pandemic.
French President Emmanuel Macron on Wednesday called Delors "a tireless creator of our Europe".
Posting on X, Macron said that "his commitment, his ideal and his rectitude will always inspire us".
Delors was "a statesman with a French destiny", Macron said.
French Socialist party chief Olivier Faure said that "a giant has left us".
Calling Delors "a child of the century" who had "experienced the worst", Faure said he had sought to "overcome tragedy by building a durable peace".
Jean-Luc Melenchon, leader of the hard-left France Unbowed party, said Delors was "a Socialist of a generation that had an ideal".
On X, Melenchon called Delors "a man of action who always thought of the common good".
Centrist Francois Bayrou said that for him "and for an entire generation of my political family and thought, he was a reference like no other".
Charles Michel, president of the European Council, said Delors was a "great Frenchman and a great European" who had "entered history as one of the builders of our Europe".
European Central Bank chief Christine Lagarde highlighted Delors's role for the single European market and "the path he laid out towards our single currency, the euro".
Europe, she said, "has lost a true statesman".
German chancellor Olaf Scholz said Delors had fought for European unity "like few others".
Calling Delors a visionary, Scholz said "it is our responsibility to continue his work for the benefit of Europe".
Ursula von der Leyen, EU Commission president, said Delors had "shaped entire generations of Europeans, including mine".
