David Koch is dead. His and his brother Charles' combined net worth is over $100 billion, even after years of family feuds and massive lawsuits. Here's how they made and spent their wealth.

David Koch is dead at age 79 , his family announced on August 23rd.

Before David's death, the Koch brothers were two of the richest people on Earth. With net worths of just over $50 billion each at the time, Charles and David Koch tied for 11th place on Forbes' March 2019 list of the wealthiest people in the world .

And they're also two of the most controversial billionaires out there, at least when it comes to their political contributions. Jane Mayer's 2015 book " Dark Money " outlined how the two Kansas natives reportedly used their fortunes to forge a formidable web of political influence, with the intent of promoting their libertarian values.

Still, that never stopped the Kochs from clashing with figures on the right, most notably US President Donald Trump. The two brothers spoke out against Trump's tariffs in the past.

So how did the Kochs come to amass so much wealth and wield such influence? The answer lies within the history of their family business: Koch Industries .

Here's a look at how the brothers became billionaires in the first place.

The groundwork for the duos wealth was laid by their father, Texas native and MIT graduate Fred C. Koch.

BusinessInsider USA Images

Sue Ogrocki/AP Images

Source: " Sons of Wichita ," " Dark Money "

The family patriarch joined the Keith-Winkler Engineering Company of Wichita, Kansas in 1925. Later that year, the firm was renamed the Winkler-Koch Engineering Company. A groundbreaking gasoline refinement technique bolstered the young company.

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Dave Miller/Flickr

Source: " Dark Money ,"" Sons of Wichita ," Fred and Mary Koch Foundation

But lawsuits from established competitors forced Koch Sr.s firm to look abroad for work. In the 1920s and 1930s, the Winkler-Koch Engineering Company ventured into a Europe on the verge of war, building refineries that proved crucial to the development of both the Soviet Union under Joseph Stalin and Nazi Germany.

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Sue Ogrocki/AP Images

Sources: HuffPost , The New York Times ," Dark Money ," NPR

In 1940, having already established himself in the industry, Koch Sr. struck out on his own and founded the Wood River Oil and Refining Company.

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Tony Webster/Flickr

Source: Lehman Brothers Collection

Six years later, Koch Sr.s company bought the Rock Island refinery in Oklahoma. The firms name switched to the Rock Island Oil and Refining Company.

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duggar11/Flickr

Source: Lehman Brothers Collection

Fred Koch Sr. went on to have four sons with Wichita native Mary Robinson: Fred Jr., Charles, and twins David and Bill. Reportedly, the Koch patriarchs namesake showed little interest in the family business, which was worth $80 million in 1960. Fred Jr. went on to become a patron of the arts.

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MSNBC/Youtube

Source: " Dark Money ," The New York Times

But Charles displayed a keen interest in the firm. In 1961, the 26-year-old second son joined his fathers company. Five years later, he became its president. Fred Sr. died in 1967, leaving Charles as the chairman.

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CBS Sunday Morning/Youtube

Source: The New York Times

After the death of Fred Sr., Charles discovered a letter that his father had written to his sons back in 1936 that contained financial advice: "If you choose to let this money destroy your initiative and independence, then it will be a curse to you and my action in giving it to you will have been a mistake."

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CBS Sunday Morning/Youtube

Source: The Seminar Network ," Sons of Wichita "

When Charles took over the private company in 1967, it was worth $250 million. The following year, the new president renamed the firm Koch Industries, to honor his late father.

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CBS Sunday Morning/Youtube

Source: " Dark Money ," The New York Times

Some of its best-known products include Dixie cups and Quilted Northern toilet paper. Koch Industries also refines crude oil and produces fertilizer.

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Flickr / ElitePete

Source: Forbes

David Koch followed his older brother into the family business in 1970. His twin Bill joined the next year, but tensions reportedly arose between the three brothers.

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Jim Cooper / AP Images

Source: " Dark Money ," The New York Times

In 1980, Bill Koch launched a coup to take over the companys board. His brothers thwarted the plan, and Bill was fired from the company with a $400,000 severance payment but the battle wasnt over.

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Richard Drew/AP Images

Source: " Dark Money ," The New York Times

Bill still owned company shares, as did Fred Jr. Contentious negotiations began between the four brothers, in a struggle that pitted Charles and David against Bill and Fred Jr. A settlement was reached in 1983. Koch Industries reportedly shelled out $620 million for Bills 21% company stake, while Fred netted $400 million for his shares, according to The New York Times.

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Mark Lennihan / AP Images

Source: " Dark Money ," The New York Times

Two years later, Bill and Fred Jr. were back in court, filing suit against their brothers. They alleged their shares had been significantly undervalued in the initial settlement. Bill also charged the company with stealing oil from federal and tribal lands. The case ultimately reached a $25 million settlement.

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Phelan M. Ebenhack / AP Images

Source: CBS , Dark Money "

In 1998, Koch Industries shelled out a $6.9 million settlement over oil spills in Minnesota, and pled guilty to a subsequent federal criminal charge, resulting in a $8 million fine.

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Mark Lennihan / AP Images

Source: " Dark Money ," Corporate Research Fund

It wouldnt be the last time Koch Industries ran into trouble. In 2002, the company paid a $28.5 million fine after one of its subsidiaries was charged with price-fixing.

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Paul Vernon / AP Images

Source: " Dark Money ," Corporate Research Fund

One of the companys biggest controversies came in 1998, when an explosion sparked by a Koch subsidiarys corroded pipeline killed two teenagers. The victims families received $296 million in a wrongful death lawsuit.

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Shutterstock/Andrey Popov

Source: " Dark Money ," Corporate Research Fund , The Washington Post , Rolling Stone

In 2000, the company paid a civil environmental fine of $30 million relating to 1995 charges over 300-plus oil spills, which the EPA attributed to Koch Industries failing to inspect its pipelines.

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REUTERS/Carlo Allegri

Source: " Dark Money ," Corporate Research Fund

But the series of litigations and settlements didnt stop Koch Industries, which has since branched into mining, real estate, and even ranching.

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The Seminar Network/Youtube

Source: " Dark Money ," Corporate Research Fund

Today, Koch Industries rakes in an annual revenue of $110 billion.

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CBS Sunday Morning/Youtube

Source: Forbes

Bloombergs most recent estimates put Davids net worth at the time of his death at $58.7 billion and Charles current net worth as the same. Forbes puts Charles net worth at $42.5 billion as of August 2019, and Davids at $50.5 billion as of March 2019. They each held a 42% stake in the family business.

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ABC News/Youtube

Source: Bloomberg , Bloomberg , Forbes , Forbes ,

David Koch was a major patron of Lincoln Center for the Performing Arts and Memorial-Sloan Kettering Cancer Center.

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Kathy Willens/AP

Source: Forbes , Forbes

"The way I look at it is, cancer research is absolutely nonpartisan," David Koch said, according to Forbes. "Cancer is very democratic in the sense that it attacks people regardless of their race, their gender, their national background, or their political persuasions."

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Getty Images

Source: Forbes

But much of the Koch brothers philanthropy is subject to controversy. The brothers both donated extensively to libertarian and Republican causes.

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Spencer Platt / Getty Images

Source: " Dark Money"

David even ran for Vice President as a Libertarian in 1980. The ticket, led by Ed Clark, won 1% of the vote.

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Associated Press/Randy Rasmussen

Source: Forbes

In 2018, Koch Industries gave $1,325,115 to federal congressional candidates. The top recipients of the Kochs money were Republicans Marsha Blackburn, Orrin Hatch, Lee Zeldin, Ron Estes, and Karen Handle.

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Drew Angerer/Getty Images

Source: " Dark Money ," Open Secrets

But the brothers political reach wasnt just a federal affair. Politico reported in October 2017 that the Kochs were attempting to sway a number of states toward committing public funding to private and charter schools.

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Diane Bondareff / Invision for Koch Industries / AP Images

Source: Politico

Closer to home, the Kochs also donated a considerable amount of money toward projects in their hometown of Wichita, Kansas. Everything from a city plaza to the local basketball arena to specific halls in the nature center bear their name.

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Nagel Photography/Shutterstock

Source: The New York Times

But, while they may have worked closely together in business and politics, the brothers were worlds apart when it came to their primary residences. Charles occupies a sprawling property in Wichita.

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Ricardo Reitmeyer/Shutterstock

Source: Charles Koch Institute , BisNow , New York Magazine

David, however, reportedly owned a massive Park Avenue duplex in Manhattan.

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Eden, Janine and Jim/Wikimedia Commons

Source: Charles Koch Institute , BisNow , New York Magazine

Prior to his death, David Koch retired from Koch Industries in July 2018 and was named director emeritus. His older brother Charles, however, remains the CEO of at the company that transformed the duo into two of the richest men to ever live.

BusinessInsider USA Images

Jamie McCarthy/Getty Images

Source: " Dark Money ," CNBC

David Koch is dead. His and his brother Charles' combined net worth is over $100 billion, even after years of family feuds and massive lawsuits. Here's how they made and spent their wealth.

The groundwork for the duos wealth was laid by their father, Texas native and MIT graduate Fred C. Koch.

The family patriarch joined the Keith-Winkler Engineering Company of Wichita, Kansas in 1925. Later that year, the firm was renamed the Winkler-Koch Engineering Company. A groundbreaking gasoline refinement technique bolstered the young company.

In 1940, having already established himself in the industry, Koch Sr. struck out on his own and founded the Wood River Oil and Refining Company.

Six years later, Koch Sr.s company bought the Rock Island refinery in Oklahoma. The firms name switched to the Rock Island Oil and Refining Company.

Fred Koch Sr. went on to have four sons with Wichita native Mary Robinson: Fred Jr., Charles, and twins David and Bill. Reportedly, the Koch patriarchs namesake showed little interest in the family business, which was worth $80 million in 1960. Fred Jr. went on to become a patron of the arts.

But Charles displayed a keen interest in the firm. In 1961, the 26-year-old second son joined his fathers company. Five years later, he became its president. Fred Sr. died in 1967, leaving Charles as the chairman.

When Charles took over the private company in 1967, it was worth $250 million. The following year, the new president renamed the firm Koch Industries, to honor his late father.

Some of its best-known products include Dixie cups and Quilted Northern toilet paper. Koch Industries also refines crude oil and produces fertilizer.

David Koch followed his older brother into the family business in 1970. His twin Bill joined the next year, but tensions reportedly arose between the three brothers.

In 1980, Bill Koch launched a coup to take over the companys board. His brothers thwarted the plan, and Bill was fired from the company with a $400,000 severance payment but the battle wasnt over.

In 1998, Koch Industries shelled out a $6.9 million settlement over oil spills in Minnesota, and pled guilty to a subsequent federal criminal charge, resulting in a $8 million fine.

It wouldnt be the last time Koch Industries ran into trouble. In 2002, the company paid a $28.5 million fine after one of its subsidiaries was charged with price-fixing.

One of the companys biggest controversies came in 1998, when an explosion sparked by a Koch subsidiarys corroded pipeline killed two teenagers. The victims families received $296 million in a wrongful death lawsuit.

In 2000, the company paid a civil environmental fine of $30 million relating to 1995 charges over 300-plus oil spills, which the EPA attributed to Koch Industries failing to inspect its pipelines.

But the series of litigations and settlements didnt stop Koch Industries, which has since branched into mining, real estate, and even ranching.

Today, Koch Industries rakes in an annual revenue of $110 billion.

David Koch was a major patron of Lincoln Center for the Performing Arts and Memorial-Sloan Kettering Cancer Center.

"The way I look at it is, cancer research is absolutely nonpartisan," David Koch said, according to Forbes. "Cancer is very democratic in the sense that it attacks people regardless of their race, their gender, their national background, or their political persuasions."

But much of the Koch brothers philanthropy is subject to controversy. The brothers both donated extensively to libertarian and Republican causes.

David even ran for Vice President as a Libertarian in 1980. The ticket, led by Ed Clark, won 1% of the vote.

In 2018, Koch Industries gave $1,325,115 to federal congressional candidates. The top recipients of the Kochs money were Republicans Marsha Blackburn, Orrin Hatch, Lee Zeldin, Ron Estes, and Karen Handle.

But the brothers political reach wasnt just a federal affair. Politico reported in October 2017 that the Kochs were attempting to sway a number of states toward committing public funding to private and charter schools.

Closer to home, the Kochs also donated a considerable amount of money toward projects in their hometown of Wichita, Kansas. Everything from a city plaza to the local basketball arena to specific halls in the nature center bear their name.

But, while they may have worked closely together in business and politics, the brothers were worlds apart when it came to their primary residences. Charles occupies a sprawling property in Wichita.

David, however, reportedly owned a massive Park Avenue duplex in Manhattan.

Prior to his death, David Koch retired from Koch Industries in July 2018 and was named director emeritus. His older brother Charles, however, remains the CEO of at the company that transformed the duo into two of the richest men to ever live.

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