Not every billionaire in the world is well-known for yacht parties and skydiving. Some of the world's richest men like to live in seclusion, take care of their families, and donate their money and time to charitable causes. Karl Albrecht is among the latter. He's the rarely seen mega-rich German, worth an estimated $27-billion.

This makes him the richest man in Germany, and among the top twenty richest in the world. Albrecht didn't create super-processing computers or build his fortune in the Stock Market. He's a “blue-collar” entrepreneur, earning his fortune from a chain of supermarkets, Aldi, which he opened with his brother Theo.

Karls Hans Albrecht was born February 20, 1920 in Essen, Germany. He and his brother Theo weren't exactly dirt poor, but their small family also wasn't well-off. Their father worked as a baker's assistant, and it was their mother who provided the influence in the household.

She owned a small grocery store, catering to the working population of Schonnebeck. Theo began working at the store at a young age, while Karl went on to work as a delicatessen. The two had no immediate aspirations of forming a business, and Karl enlisted in the Army during World War II.

After the war was over, the two brothers reunited and took over their mother's store in 1946. Together, the brothers tried out a host of new ideas to lure in new business, and slowly but surely, the small corner store became a huge success in the area. It was this that prompted the young men to try their hand at opening a larger store. “Aldi” an acronym meaning “Albrecht Discount” was opened in 1961.

Their flagship grocery did very well, and the idea of expansion was immediately on the table. They now had two stores, and Karl took control of Aldi south while Theo took the reigns for Aldi north.

In only a few short years, the stores started to expand, and by 2000, Aldi had over 4,000 stores in Germany alone. Albrecht's grocery stores can also be found globally. They have many stores in Demark, France, Poland, the UK, Greece, Switzerland, Hungary, Australia, the United States, and other countries.

Although the brothers both appear to own the “same” stores, they're actually completely separate from one another. Karl controlled Aldi Sud (south), which has the primary global interest, whereas Theo ran Aldi Nord (north) which doesn't have quite the global appeal, but still does extremely well. Together, the stores rake in billions annually, and the Aldi brand is worth almost $60-billion.

Karl and Theo have since given up the operations of their stores. In 1994, Karl resigned himself from the day-to-day operations to take over the position of chairman, but left that at the beginning of 2002. He still makes money from the stores, however, pulling in an estimated $1.5-billion annually. No one in the Albrecht family works for Aldi in any capacity - they're officially retired and live normal, private lives in Germany.