They're the heirs to the chocolate throne that is Mars Inc, maker of Snickers, Mars Bars, Milky Way Bars, Twix, M&M's, and more - not to mention a portfolio of PetCare products, drinks, and chewing gum, among others.

The 106-year-old company, which has a factory and is home to research and development in Ballarat, has helped the Mars family build a reported fortune of $US89.7 billion ($127 billion), according to Bloomberg.

The six family members who rank on the Forbes 400 list share $US72 billion of that fortune, making them America's third-richest family wealth "dynasty", according to the Institute for Policy Studies'"Billionaire Bonanza" report.

Press-shy and limelight-avoidant, the Mars family remains a bit of a mystery. They have been known to keep the company "notoriously private" and their headquarters have been called "anonymous".

However, Mars has more recently started trying to shed its secretive history. During the last few years, the Mars family and company executives have started to speak out.

Here's what we know about the Mars family and Mars Inc.

The Mars family's fortune is rooted in its family-owned chocolate empire, Mars Inc. Founder Frank Mars learned to hand-dip chocolates at a young age; in 1911, he began selling chocolate from his kitchen in Tacoma, Washington.

During the Depression, founder Frank and wife Ethel became "social luminaries". They owned a $US20,000 Deusenberg town car and had two getaway homes in Wisconsin and Tennessee.

They also opened their Tennessee getaway home, the Milky Way Farms Racing Stables, to the public for fundraisers and public events. Ethel's horse won the Kentucky Derby in 1940, securing her "station in mint-julep society".

They made the first chocolate nougat, setting the foundation for Milky Way Bars and Snickers. However, Forrest snr fell out with his father and in 1932, he was given the recipe for the Milky Way Bar to start his own business.

Since then, the company has become known for the eponymous Mars Bar, 3 Musketeers, Twix and M&Ms. More than 400 million M&Ms are produced in the US every day.

The company's secrecy dates back to when Forrest snr patented the method for Uncle Ben's rice and American military chiefs tried to overturn the patent to supply troops. Forrest snr reportedly avoided photographers and interviews alike.

Unlike his parents, Forrest snr was relatively frugal. He raised his children the same way - while they attended exclusive boarding schools, they did chores at home to earn an allowance. However, he did buy a 740-acre farm in Virginia in the 1940s. He and his wife, Audrey, lived apart for a lot of their marriage - she kept a penthouse apartment at The Watergate.

Forrest snr has been described as having an "extreme temper", but was separately praised as "one of this century's most brilliant and successful entrepreneurs" by Fortune magazine in 1984.

"He was an iconic leader - dedicated and highly respected," a Mars spokesperson told Business Insider.

When Forrest snr died in 1999, his children - Jacqueline, John, and Forrest jnr Mars - inherited a stake in the company. Forrest jnr passed away in 2016. Currently, Jacqueline and John co-own, but don't actively manage, Mars Inc. They have the biggest share of the family fortune, with $US24 billion each.

They rank on the Forbes 400 along with Forrest jnr's four daughters, who have $US6 billion each after each inheriting an 8 per cent stake. The collective fortune of all six is $US72 billion, making them the third-richest family "dynasty" in the US, according to the Billionaire Bonanza report.

Jacqueline is the only sibling with a lifestyle "close to reflecting her billionaire status", wrote Jan Pottker for The Washingtonian in 2008. She reportedly listed her estate in New Jersey for $US2 million, has a place called Stonehall Farm in Virginia, and maintains her mother's Watergate penthouse. Like her family, Jacqueline maintains privacy.

In 2013, Jacqueline was involved in a car crash in Loudon County. She was driving her Porsche SUV "when her vehicle crossed the centre line and hit an eastbound minivan", according to authorities.

"According to authorities, Mars told a witness who went to the scene of the accident that she had fallen asleep while driving," wrote Caitlin Gibson of The Washington Post. "Tests revealed no trace of drugs, alcohol or medications that could have caused a blackout ... Witnesses said that Mars was not speeding or driving erratically before the accident."

The accident occurred in Loudon County; the driver of the other car lost her unborn son, a passenger died, and other passengers were injured. The victims urged the court not to seek jail time for Jacqueline, who pleaded guilty. She was ordered to pay a $US2500 fine.

"I can't go back in time. I can't change what happened," Mars, who planned to help the family, said in a statement. "I will always live with the grief and loss caused by this tragedy."

Jacqueline and her ex-husband David Badger have three children. Their son, Stephen Badger, is the chairman of Mars Inc. Recently, the company has started to open up about its business to be transparent to consumers and attract talent, Badger told Business Insider.

"For most of our history, in fact ... for 99 per cent of our history, we've chosen not to be in the public eye and we've really wanted our brands to engage consumers. And yet times have changed," Badger said.

Not much is known about Jacqueline's brother John, but in March 2015, he was made an honorary knight by Queen Elizabeth II. Both he and Jacqueline run the Mars Foundation, which donates to educational, environmental, cultural, and health-related causes. The company also has a volunteer program.

Both John and Forrest jnr inherited their father's tendency to avoid the spotlight. And their father's frugal ways stuck with them: both brothers reportedly lived in relatively affordable condos.

"When I was growing up it felt very normal," Forrest jnr's daughter, Pamela Mars, told Campden FB. "I didn't feel different to anybody else. We did chores around the house, we went to school. We didn't live a different lifestyle to any of my friends."

When Forrest jnr passed away, his four daughters - Victoria, Valerie, Pamela, and Marijke - inherited an equal stake.

Victoria is the former the chair of the board of directors of Mars Inc. A spokesperson for Mars told Business Insider that there are six rotating positions on the board.

Growing up, Pamela lived in Holland and France for several years before moving back to the US for her father's various Mars Inc jobs. After graduating from Vassar and a stint working in advertising, Pamela joined the family business as an operations supervisor. She moved up the ranks, and after a sabbatical, became chairman of the board, a position from which she later stepped down.

According to Forbes, Valerie and Marijke both work at Mars and serve on the company's board of directors.

For years, the family was known for being "notoriously private", keeping their personal lives and Mars Inc out of the public eye.

"The Mars company and the family that owns the confectionery giant have turned secrecy into a way of life," wrote Pottker. Morningstar food analyst Mitchell Howard called Mars a "very, very quiet company".

Nicknamed "the Kremlin", the Mars Inc headquarters are based in the Virginia suburbs and have been described as "secretive" and "anonymous".

Today, four business segments comprise Mars Inc: petcare, Mars Wrigley Confectionery, food and edge.

In 2008, Mars Inc branched out from chocolate to gum when it acquired the Wrigley Jr Company for $US23 billion, and it bought Iams and two other pet food brands in 2014 from Procter & Gamble for close to $US2.9 billion.

Now a $US35 billion firm, Mars is the fifth-largest private business in the United States, and it was previously ranked as a best place to work by Fortune magazine.

Mars Inc says it can attribute its success to the five principles that Pamela Mars called the bedrock of the company: quality, responsibility, mutuality, efficiency and freedom.

Jacqueline also supports the US Olympic Equestrian Team and is a trustee of the US Equestrian Team Foundation. She sits on several boards, including the National Sporting Library and Fine Art Museum, the Smithsonian and the American Prairie Reserve.

According to a Mars spokesperson, she received the first-ever Foundation for the National Archives' "Heritage Award", for her support of the National Archives and other arts and cultural institutions in Washington, DC. She also played a role merging the Opera with John F. Kennedy Center for the Performing Arts and made a multi-year commitment to support the Washington Performing Arts' programs.

"The family has always believed that the biggest contribution toward the world we want tomorrow is through the good that Mars Inc can do every day, and the family reinvests the vast majority of any profit made back into the company," a company spokesperson told Business Insider.

And in 2017, the company made a $US1 billion investment in a sustainability program that will contribute to the UN's Sustainable Development Goals and the Paris Climate Agreement.

While the Mars family has remained private over the years, it's helped them keep their anonymity, Joseph Astrachan, an expert in family enterprises, told The Guardian. But one thing will always remain private: the company itself.

"The philosophy of the family and the philosophy of the business is that it's a family business," Pamela told Campden FB. "More importantly, it's a privately held business and that's the way that we'd like to keep it."

- Business Insider