Otto Beisheim probably owns more retail stores, department stores, and businesses than he could remember off the top of his head. Which is really not that bad for somebody whose parents were too poor to send him to a high school.

Son of an estate manager, Beisheim was born in 1924. As a young man, he was trained in the leather industry, but he quickly realized that that profits in retailing electronics would be much higher. In 1964, he became independent and, following a trip to the United States, founded the first German cash-and-carry market, proving himself to be a brilliant organizer and financial expert.

From then on, his professional life became an ongoing saga of mergers and acquisitions, market conquests and clever marketing campaigns. As founder and stake holder in Metro AG Group, Beisheim employs some 250,000 people in more than 2,400 cities in 30 countries.

It would be practically impossible to find a German who hasn't shopped in Kaufhof department stores, Extra and Real supermarkets or the MediaMarkt electronics chain.

Beware of Germans Carrying Gifts

Beisheim's wealth has been estimated to $3.4 billion (2.9 billion euros). Having invested 500 million euros in a 70 meter tall Beisheim Tower on Berlin's exclusive Potstamer Platz -- part of a complex including two five-star hotels and the most expensive apartment building in all of Germany -- Beisheim also became the largest private investor in the German capital.

If he has a weakness, it is having buildings named after him. His hefty donations in the educational sector have landed him honorary titles, seminar and colloquia series, as well as an Otto Beisheim School of Management.

But his decision to award 10 million euros to Tagernsee High School in return for having his name on a golden plaque ended in a fiasco and public scandal, after some of the teachers questioned the moral aspects of such a gift.

Beisheim is believed to have been a member of Hitler's SS fighting unit during the war. He refuses not only to talk about that period of his life, but also to allow anybody -- especially those who'd benefit from his wealth -- to question his past. After the Tagernsee school asked for a proof of his innocence in November 2005, Beisheim revoked his generous offer and decided to take his money elsewhere.

Students and parents then organized demonstrations in which they carried around posters with cheesy slogans in support of "dear grandpa Beisheim," but that didn't change his mind. One of the privileges of being rich and powerful is that you can always act on your own terms.