The world's 10 wealthiest families are spread across four home countries. They include royalty, the pioneers of international finance, generations of entrepreneurs and even a candy maker. One out of 10 is headed by a woman. Two found wealth through politics and privileged access to resources, and one employs more than 2 million people. Each family is worth at least $34 billion, but the top two may each be worth more than $1 trillion. All estimated net worth figures were calculated in March 2016.

The Rothschild Family, Germany

Estimated Net Worth: $350 billion - $2 trillion

The Rothschild name has been associated with international banking since at least the late 1700s. Mayer Rothschild, the original patriarch, was a favored assistant and finance manager of the German royal family. He leveraged his position in court to develop a banking business for the German aristocracy. When his five sons reached adulthood, they were stationed in Frankfurt, London, Naples, Paris and Vienna to manage local banking affairs. From there, a multi-century financial empire flourished.

Due to their relatively low profiles and private business activities, the Rothschilds have captured the imagination of financial historians and conspiracy theorists alike. It is difficult to track and verify their various holdings among so many descendants, but they are still fabulously wealthy. The family motto is: Concordia Integritas Industria, meaning "Harmony, Integrity, Industry."

The House of Saud, Saudi Arabia

Estimated Net Worth: $1.4 trillion

The al-Saud family has ruled Saudi Arabia with absolute authority since the 1700s, though the modern government has been in place since 1932. As of 2016, the al-Saud family is headed by King Salman bin Abdulaziz al Saud. Not surprisingly, most of the al-Saud wealth comes from its control over Saudi Arabia's oil reserves.

The Walton Family, US

Estimated Net Worth: $152 billion

Sam Walton built his family's retail shopping empire over a relatively short period of time. He cut his teeth in variety store franchises in the late 1940s and early 1950s. In July 1962, Walton opened the first Walmart store, then called Walmart Discount City, in Rogers, Arkansas. As of 2016, the stores operate under Wal-Mart Stores Inc. (NYSE: WMT). Walton revolutionized the industry, avoiding larger urban competition and focusing on small towns. He mastered distribution, selection and supplier contracts. His six heirs own 54% of WMT stock. The company is the largest nongovernment employer in the world, with an estimated 2.1 million employees in 2015.

The Koch Family, US

Estimated Net Worth: $89 billion

Koch Industries, the second-largest private company in the world, is a multinational conglomerate with interests in oil, real estate, ranching, commodity trading, chemicals, finance, fertilizer and household items. Fred C. Koch launched the company as an oil refinery in 1940, but it really took off under the control of his sons Charles and David, who bought out brothers Bill and Frederick in 1983.

The Mars Family, US

Estimated Net Worth: $80 billion

The Mars family drew most of its fortune from candy. Mars Inc. is the world's largest private candy company, and it has been putting sweets on shelves since 1911. Franklin Mars founded the company, but son Forrest is credited with adding the Mars Bar and M&Ms.

The Slim Family, Mexico

Estimated Net Worth: $77.1 billion

Carlos Slim Helu was Forbes Magazine's fourth-wealthiest person in the world for 2016. He ranked first between 2010 and 2013. Slim founded Grupo Carso, a conglomerate that controls approximately 40% of the equity value on the Mexico Stock Exchange. He runs the empire with the help of his sons.

The Cargill-MacMillan Family, US

Estimated Net Worth: $45 billion

The only private company worth more than Koch Industries is Cargill Inc., founded by William Wallace Cargill in 1865. Eighty-eight percent of the company is owned by the Cargill-MacMillan family. This family boasts more known billionaires, 14, than any other family in the world.

The Bettencourt Family, France

Estimated Net Worth: $42.7 billion

In 1909, a young French-German chemist named Eugene Schueller developed a unique hair dye formula. Since Paris was the fashion capital of the world at the time, Eugene found a natural market among wealthy Parisians and hair salons, which eventually grew into cosmetics giant L'Oréal S.A. (OTC: LRLCY). His daughter, Liliane, eventually assumed control over the company after the deaths of her father and husband Andre Bettencourt. As of 2016, Liliane Bettencourt is the wealthiest woman in the world.

The Arnault Family, France

Estimated Net Worth: $37.7 billion

Another billionaire French family, the Arnaults are best known for luxury brands Moet Hennessy Louis Vuitton (OTC: LVMUY), or LVMH, and Christian Dior. The family patriarch, Bernard Jean Etienne Arnault, is still chairman and chief executive officer (CEO) of LVMH. His two children, Antoine and Delphine, are also active in the company.

The Cox Family, US

Estimated Net Worth: $34.5 billion

The Cox family, not unlike the al-Saud family, learned how to transform government access into generational wealth. James Middleton Cox served two nonconsecutive terms as the Democratic governor of Ohio and ran a failed campaign for president in 1920. After politics, he acquired a few newspapers and built a media brand, all while remaining close to the Democratic party establishment and Franklin D. Roosevelt, whom Cox had chosen as his running mate in 1920. As of 2016, Cox Enterprises is run by two of Cox's grandsons.

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