(NBC NEWS) — David Koch, billionaire conservative activist and philanthropist, has died. He was 79.
“It is with a heavy heart that I announce the passing of my brother David," Charles Koch said in a statement Friday. "Anyone who worked with David surely experienced his giant personality and passion for life."
David and Charles co-owned Koch Industries, a Kansas-based energy and chemical company, since 1983. David stepped down from running the Koch organization last year due to declining health.
The brothers tied as 11th richest in the world in a ranking by Forbes.
With the billions from their business, the Koch brothers helped to build a massive conservative network of donors for organizations that work to mobilize voters and sway elected officials in support of libertarian-leaning economic policies.
The network, led by the nonprofit Americans for Prosperity, has spent more than $1 billion over the past several elections to support candidates that adhere to their free-market, small government libertarian ideals.
The organization sometimes split with the GOP under President Donald Trump. It launched a multimillion dollar campaign last year promoting free trade and warning against tariffs.
David Koch, a prostate cancer survivor, also donated hundreds of millions of dollars to medical research. He was also a huge supporter of the arts in New York City, notably donating to Lincoln Center and $65 million to support a renovation of the Metropolitan Museum of Art.
When Koch was diagnosed with cancer 27 years ago, he was given five years to live, his brother said.
"David liked to say that a combination of brilliant doctors, state-of-the-art medications and his own stubbornness kept the cancer at bay," the brother's statement said. "We can all be grateful that it did, because he was able to touch so many more lives as a result."
