David H. Koch, executive vice president of Koch Industries Inc. and a long-time philanthropist, has died at age 79.

His older brother, Charles, the death on Friday, saying, “It is with a heavy heart that I now must inform you of David's death.”

Koch amassed his vast wealth with a large ownership stake in Koch Industries, the Wichita, Kansas-based company he ran with Charles.

With Charles as chairman and chief executive and David as executive vice president, Koch Industries — one of the world's largest privately held businesses — aggressively expanded beyond the oil refining business their father created into an array of new ventures.

David Koch stepped down from the business and political activities in June 2018, citing declining health.

A billionaire who lived in New York City, he was the Libertarian Party's vice presidential candidate in 1980. He was a generous donor to conservative political causes as well as educational, medical and cultural groups.

The Koch brothers were best known for a vast political network they built that became popularly known as the “Kochtopus” for its far-reaching tentacles in support of conservative causes. The brothers founded the anti-tax, small government group Americans for Prosperity.

“I was taught from a young age that involvement in the public discourse is a civic duty,” David Koch wrote in a 2012 op-ed in the New York Post.

“Each of us has a right indeed, a responsibility, at times to make his or her views known to the larger community in order to better form it as a whole. While we may not always get what we want, the exchange of ideas betters the nation in the process.”

After battling prostate cancer for 20 years, he told a reporter following the 2012 Republican convention that he was thinking about what he will someday leave behind.

“I like to engage where my part makes a difference,” he told The Weekly Standard. “I have a point of view. When I pass on, I want people to say he did a lot of good things, he made a real difference, he saved a lot of lives in cancer research.”

David Koch donated $100 million in 2007 to create the David H. Koch Institute for Integrative Cancer Research at the Massachusetts Institute of Technology. He also gave millions to Johns Hopkins University in Baltimore, the Memorial Sloan-Kettering Cancer Center in New York City, the M.D. Anderson Cancer in Houston, and other institutions.

The Smithsonian's National Museum of Natural History named in his honor a wing dedicated to the story of human evolution over 6 million years. David Koch donated $15 million to fund the 15,000 square-foot hall.

“The programme has the power to influence the way we view our identity as humans, not only today, but for generations to come,” he said in a statement at the time.