Francois Mitterrand's name will forever be associated with the grands projets (literally "big projects") he built in Paris. And that is what he intended - to out-do Louis XIV and even, perhaps, Napoleon III in leaving his mark on the French capital.

As a socialist, he was determined in particular to trump his Gaullist predecessors, whose party regarded him as a usurper of its divine right to rule France. Thus, as soon as he took office in May 1981, he set about creating great monuments that would be in place for the bicentenary of the French Revolution.

According to Marie Delarue, author of a book on Mitterrand, Un Pharaon Republicain, the grands projets are all "monuments to utopian egalitarianism", commissioned by a head of state who saw great architecture as the embodiment of culture, to be used to embellish Paris as a world capital par excellence. The story of how his most popular grand projet - the Pyramid at the Louvre - materialised is well-known. On his first visit to the US as President of France, he made a point of touring I M Pei's National Gallery in Washington DC and was so impressed that he invited the architect to Paris to talk about the Louvre.

The old royal palace, multiply extended over the centuries, was barely functional as a museum. Its Richelieu wing extending along the Rue de Rivoli was occupied by the Ministry of Finance and the rest of it was an endless series of rooms, corridors and staircases. What Mitterrand asked Pei to do was to make sense of it all.

His proposal for a glass pyramid in the centre of the Cour Napoleon, to provide a new entrance to the museum, was extremely controversial, though its Pharaonic form appealed to Mitterrand. And to satisfy himself about its aesthetic qualities, he decreed that a full-scale mock-up should be erected on the site for his personal inspection.

When the Pyramid and its attendant triangular pools were completed in 1989, the critics were silenced. It became, in Stephen Gardiner's phrase, "the diamond of Paris". And the vast concourse underneath cleverly unified the three main wings of the Louvre, making it much easier for throngs of visitors to find their way around.

The Ministry of Finance was moved to a vast, elongated new building at Bercy and the Louvre later acquired a high-vaulted underground shopping mall with an inverted pyramid as its centre-piece.

The only sour note was that Pei copyrighted even postcard images of his Pyramid, giving no credit to RFR, its structural engineers.

The Grand Louvre cost some six billion francs (£720 million), yet it was merely the first of Mitterrand's grands projets. Others included the Grand Arche at La Defense, Jean Nouvel's shimmering Institut du Monde Arabe, the "People's Opera" at the Bastille, the redevelopment of Parc de la Villete and the Bibliotheque Nationale.

The cube-like Grand Arche consists of two 35-storey office buildings joined together at the top with a "cloud" suspended in between over a broad flight of steps. Not only does it provide a much-needed focal point for the high-rise office cluster in La Defense but also a dramatic new terminus for the great axis of Hausmann's city.

By comparison, the Opera plonked on one side of Place de la Bastille seems elephantine. Its design was chosen "blind" by the jury of a major international competition, who thought that its whiteness indicated the work of Richard Meier - whose work Mitterrand admired - but it was actually done by a Uruguayan Canadian, Carlos Ott.

"His name is OTT - and it is!" Dublin architect Alfred Cochrane quipped after the Opera was completed in 1989. Worse still, much of the stone cladding on its lower levels has since failed and is now covered in wire mesh to prevent defective panels falling into the street. Repairs could cost up to 100 million francs (£12 million). But then, the Centre Pompidou - designed by Richard Rogers and Renzo Piano for one of Mitterrand's predecessors - had to be totally renovated not much more than 20 years after it was completed in 1977. This hi-tech behemoth, with all of its innards hanging out, did wonders for its quartier because it gave so much to the public.

Though removed somewhat from the city centre, Parc de la Villette - developed on a vast slaughterhouse site to a trendily deconstructivist design by Bernard Tshumi - is regarded as a success. Its principal attraction, the Cite des Sciences, has pulled in the punters to an area that previously registered blank on the map of Paris.

The Parc Andre Citroen and Parc du Bercy, though hardly classified as grands projets, have been hugely influential in redefining the very idea of public parks. And the remaking of the Champs Elysees - admittedly by Jacques Chirac when he was Mayor of Paris - set new standards for paving and street furniture in the city.

Neither has Paris neglected its metro. The newest Meteor line, running from Madeleine to Bibliotheque, is a marvel of sleek driver-less trains hurtling through a tube and stopping with synchronicity in state-of-the-art stations. Unlike London, public transport has always been valued in the French capital, whoever rules the roost. Mitterrand's maddest project was the Bibliotheque Nationale. The idea had come to him in a dream, as he told the press, but it turned into something of a nightmare - largely because of the preposterous scheme by Dominic Perrault, which won an international competition for the design of this "TGB" (Tres Grand Bibliotheque).

Four L-shaped glass towers, meant to symbolise open books, rise from a vast podium on the site at Tolbiac, on the left bank of the Seine, opposite Bercy. The podium is hollowed out to create a large rectangular courtyard at the same level as the river, filled with Mediterranean pines which seem a long way from home.

The idea of storing books, including rare ancient volumes, in 22-storey glass towers was ridiculous in itself - timber louvres had to be added to protect them from the sunlight - and meant that every book ordered by a reader had to travel long distances on a computer-guided tracks to the vast reading rooms at basement level.

Fritz Lang's Metropolis seems to have been the inspiration for the interiors, with walls covered in roughly-cut panels of wire mesh like medieval chain mail and concourses so enormous that they might have been borrowed from Nicolai Ceaucescu's palace in Bucharest. The overall effect is as oppressive as it is non-functional.

Built for eight billion francs (£960 million), the TGB represents folie de grandeur - much like Sports Campus Ireland. But perhaps Paris can afford to make expensive mistakes. It has such remarkable coherence as a city, and such a breathtaking accretion of monuments, that it will always remain the cultural capital of Europe.