His collection was probably the world's largest in private hands. Numerically if not qualitatively speaking, his donations to public institutions were of unparalleled magnitude. So were the controversies he ignited.
Ludwig's eminence and the wealth which made it possible were characteristic products of the post-war Wirtschaftswunder. During a period in which cultural activity of every kind came to be regarded as the most convincing evidence of prosperity and democratic stability, patrons like him were courted by politicians and lionised by the press. With the help of men like him, museums rebuilt collections ravaged by the Nazis and regained their reputations as champions of whatever was experimental and new. At such a time even egocentricity could seem public-spirited.
Born in Koblenz in 1925, Peter Ludwig, whose father was a cement manufacturer, grew up in a financially secure and cultivated atmosphere. His brother was eventually chosen to run the family business, and Ludwig's own career began to burgeon only in 1951 after he married Irene Monheim, the daughter of one of Germany's most successful chocolate makers. A year later he was appointed managing director of Monheim Schokolade, based at Aachen, and in 1969 took control as chairman.
Ludwig had met Irene Monheim while both were studying art history at Mainz University. Ludwig wrote a dissertation on Picasso (a subject which, he claimed, was then daring and controversial), and graduated with a PhD. His critics, and there are many, later claimed that the expert knowledge supposedly acquired at university had not prevented him from buying paintings by Picasso that are exclusively second-rate.
While Ludwig was improving the performance of Monheim Schokolade (largely by introducing cheap brands which eventually acquired 20 per cent of the home market and made inroads abroad, even behind the Iron Curtain), he and his wife devoted much of their energy to their growing art collection which was as varied as it was large, the result of changing interests and enthusiasms. Porcelain and Delft tiles were followed by rare editions, Pre-Columbian, medieval and than Classical art. But it was Ludwig's acquistion of American Neo-Dada and Pop Art which first brought him to public attention and made him a celebrity.
At the height of his activities in the mid-Seventies Ludwig was buying on average a work of art every single day. His vast collection not only decorated the company offices and his home at Aachen but was loaned to museums in Germany and abroad. Often the loans became gifts and the museums changed their names in recognition of Ludwig's great generosity.
Today there are no fewer than 30 Ludwig Museums in Germany and abroad, for example in Cologne, Aachen, Vienna and Budapest. Another will open later this year in Beijing. Other museums - in Basle and St Petersburg, for example - have Ludwig to thank for a substantial part of their collections.
Peter and Irene Ludwig collected honours as voraciously as they did art. Grateful countries and cities arranged for honorary doctorates and professorships which, in Germany, are taken as seriously as aristocratic titles are elsewhere. Certainly the Ludwigs liked to be addressed as Herr and Frau Professor.
Other honours were more practical. It is said that following a series of gifts of Classical Greek and Roman art to the Antikenmuseum at Basle (which subsequently restyled itself the Antikenmuseum and Ludwig Collection), Peter Ludwig became the only foreigner for whom Swiss immigration and customs regulations were officially and permanently waived.
Ludwig's supporters describe him as a great, pioneering collector and connoisseur. They argue, not entirely persuasively, that he was the first to recognise the merit of American Pop Art and acquire it in substantial numbers. With more justice they also point out that he was among the first to buy Soviet Socialist Realism and East German art and provide a Western public with the opportunity to see and judge it for themselves. Supporters also maintain that Ludwig used his collection to raise Germany's cultural profile, improve international relations, and heighten the general awareness of modern art.
Ludwig certainly encouraged the German government and municipal authorities to take the visual arts more seriously, and he pulled off some spectacular coups abroad. The most startling was the Ludwig Room in the East Berlin National Gallery. There, at the end of galleries stuffed with dispiriting examples of political realism, a room full of works by Warhol, Lichtenstein, Rauschenberg and others, all borrowed from the Ludwig collection, gave East Germans their only taste of American painting and modern Western art. The loan was said to have been negotiated as part of a deal to supply the East German army with chocolate.
Ludwig's dealing with East Germany and the suspected motivation behind them attracted criticism. His political sympathies were questioned as, more importantly, was the way he seemed to be using his collection to benefit his business. Indeed, the director of Cologne's Ludwig Museum resigned rather than submit to the collector's demands that East German art be exhibited there.
More damaging attacks on Ludwig were launched in 1986 when he rashly commissioned Arno Breker, once Hitler's favourite sculptor, to make bland portrait busts of himself and his wife. When he offered them to the Ludwig Museum in Cologne to decorate its entrance hall there was a storm of protest. During the subsequent controversy he claimed that Breker was one of the greatest sculptors of the century, that not all Nazi-approved art was bad, and that it should once again be on show in German museums. This harmed his reputation as a connoisseur irreparably.
Ludwig's critics then had a field day. They pointed out that many of the works he owned were of dubious quality, and that he used loans and hints of gifts to public collections not only to influence their policy but also to enhance the financial value of his collection.
Critics recalled an earlier, similarly revealing controversy. Having amassed a large collection of medieval art with the assistance of the director of the Schnutgen Museum in Cologne (who was given unambiguous signals that a long loan would eventually become an outright gift), in 1983 Ludwig removed it. He shifted some of the collection to his foundation at Aachen and sold the superlative manuscripts to the Getty Museum at Malibu for a rumoured $40m. Few were convinced by his claims that he urgently needed funds to help his business weather the recession. He was investigated by German tax authorities, who dropped proceedings after Ludwig agreed to pay a large fine.
All art collectors, especially those who buy in enormous quantities, make mistakes, and Ludwig made more than his fair share. In spite of his reliance on unpaid specialist advisers, most of them scholarly museum curators, he had his blind spots. He thought abstraction had had its day, had no sympathy for conceptual art, and too often acquired whatever was fleetingly fashionable. His own taste was for the representational; hyperrealism, or, indeed, the realist painting encouraged in the Soviet satellites.
Six foot two inches tall and avuncular in manner, Ludwig relished the attention and influence his collection brought him. He died knowing that, through the many museums named after him, he had achieved a kind of immortality. But he must also have suspected that he would eventually be seen as representative of a bizarre artistic climate in which an enormously wealthy collector can become more celebrated than the artists whose work he acquired.
Peter Ludwig, art collector: born Koblenz, Germany 9 July 1925; married 1951 Irene Monheim; died Aachen 22 July 1996.