Fortunes are made and lost all the time. Going up and down with economic bubbles and crashes, strokes of genius or simply strokes of luck, wealth is sort of a roller-coaster ride and doesn’t always really make it from one generation to another. But when it comes to the people on this list, it seems that money is something that just, well, runs in the family.

10. Dassault Family – $15 billion

When Serge Dassault inherited his father’s fortune, he not only received a major weapons manufacturing company, he also got his father’s badass name, which comes from the French char d’assaut, which literally means battle tank (a name he preferred to his original Bloch). Today, Dassault Group is a vast conglomerate with operations in the aviation industry (kind of ironic, if you consider the owner’s last name), aerospace equipment, and even in media and sports.

9. Cargill Family – $ 23 billion

The Cargill family owns 90% of the largest privately held company in the US., Cargill, Inc. The company’s most important business is in agriculture. Like most other families in the list, the Cargills started off small about a hundred years or so (in their particular case it was a bit earlier, with William W. Cargill buying a grain storage house in Iowa after the America  Civil War), and now the founder’s grandchildren jointly own one of the biggest companies in the world.

8. Thomson Family – $26 billion

The richest family in Canada holds most of their wealth in media, most notably owning Reuters. The family fortune was started* by Roy Thomson in the early 1930s, who basically created a media empire from nothing and eventually received the title of Baron for public services. His grandchildren now control most of that wealth, the most prominent among them being David Thomson. Most of the family investments are made through the Woodbridge Company, a private holding company based in Toronto, Canada.

7. Bettencourt Family – $32 billion

The Bettencourt family owes their wealth to the cosmetics giant L’Oreal. Liliane Bettencourt is the company founder’s only daughter, and by inheriting her father’s wealth she became the richest person in France and the world’s third richest woman. All her fortune has not shielded her from controversy however. Her husband was accused of collaborating with the Germans in World War II, while her daughter has tried to wrestle control of her vast fortune from her, alleging she is mentally unfit to manage it herself.

6. Albrecht Family – $36 billion

The Albrecht brothers, Karl and Theo, founded the German discount supermarket chain Aldi. What started off as a small store opened by their mother in their hometown of Essen in 1913 was eventually built up by the brothers into one of the most successful businesses in Germany and in Europe. In 1960, the brothers split the company in two and have went their own ways ever since. Karl is currently the richest person in Germany and one of the 5 wealthiest people in Europe. Since Theo died in 2010, his fortune has passed to his sons, of which only Theo Jr is still alive today, running the family business.

5. Quandt Family – $40 billion

Most of the Quandt family wealth comes from their joint ownership of nearly half of German luxury automobile manufacturer BMW. Johanna Quandt was married to Herbert Quandt, one of the sons of the company’s founder, who managed to reverse BMW’s fortunes during some rough times in the ‘50s. She shares most of the inherited wealth with their children, Susanne Klatten and Stefan Quandt.

4. Mars Family – $66 billion

One of America’s lesser known wealthy families, the Mars brothers (Jacqueline, John and Forrest Jr) are as protective of their privacy as they are good at protecting and expanding their inherited wealth. They jointly own the third-largest privately held company in the US, Mars, Inc., mostly known for its confectionery items (like M&M’s, Skittles, the Mars bar), but also other foods and pet food. The Mars brothers are so secretive that not only do they not give any interviews, they don’t even allow photographs to be taken of them (with the exception of Jacqueline).

3. Koch Brothers – $90 billion

The Koch Brothers, Charles and David, currently own most of the second largest privately held company in the United States, Koch Industries. Built by their father, Fred Koch, who developed an innovative way to refine oil into gasoline in the ‘20s, the company is the most important source of their wealth. The brothers have used to massive wealth most notably on the political scene, where they very publicly provide funding for various mostly conservative causes, but have also bankrolled many charitable causes (David Koch, a cancer survivor, has given hundreds of millions to cancer research).

2. Walton Family – $150 billion

When you think of an incredibly successful and rich family, you think of the Waltons. Sam Walton has built a retail store empire with Wal-Mart, and now his family is reaping the benefits. If they were a single person, that person would be by far the wealthiest person in the world, doubling the net worth of the current richest man in the world, Bill Gates. Even with the fortune divided between them, each of Sam’s heirs is easily in the top 20 of any billionaire rich list.

1. Al Saud Family – $1.4 trillion

The House of Saud, the ruling family of Saudi Arabia, has been leading the oil-rich Middle Eastern nation for 250 years. They are so wealthy that they’ve literally broken the meter, making their net worth basically impossible to determine (in part because there’s a fuzzy distinction between personal assets and what belongs to the state). Two of the more public members, Kind Abdullah and Prince Alwaleed are both very high on the word’s billionaire list, worth 20 and anywhere between 25 and 30 billion dollars, respectively. While there’s no way to know for sure how much each of the thousands of members of the royal family has accumulated, the country still has trillions of dollars worth of oil reserves. And with no clear line between what belongs to the Saudi state and what belongs to the Saudi royalty – well, you do the math!