Conservative icon and philanthropist David Koch died at age 79 Friday, his older brother Charles Koch announced in a statement.

Last summer, Charles Koch notified officials of Koch Industries, the Koch family’s Kansas-based energy and chemical corporation, that his brother was suffering deteriorating health after he was diagnosed with advanced prostate cancer twenty-seven ago.

David Koch then retired from running the family business, citing health reasons.

“Anyone who worked with David surely experienced his giant personality and passion for life. Twenty-seven years ago, David was diagnosed with advanced prostate cancer and given a grim prognosis of a few years to live. David liked to say that a combination of brilliant doctors, state-of-the-art medications and his own stubbornness kept the cancer at bay. We can all be grateful that it did, because he was able to touch so many more lives as a result,” Charles Koch said.

David and Charles Koch were tied as the 11th richest in the world in a 2019 ranking by Forbes.

David Koch, a New York resident, was worth $42.4 billion and became a household name through the political empire he created with Charles. The Koch brothers, who were denigrated by Democrats, are best known for developing a massive network of conservative think tanks, foundations and political groups that helped mobilize voters and sway elected officials into supporting free-market, and small government economic policies.

The network, led by the nonprofit Americans for Prosperity, built a coalition of more than 3 million activists, spending over $1billion during the 2016 election, to advance libertarian, limited government principles.

In, 1980, David Koch waged an unsuccessful bid as the Libertarian Party’s vice presidential nominee with Ed Clark. They won just 1 percent of the vote.

Koch donated $65 million to support renovation of the Metropolitan Museum of Art. Lincoln Center’s David H. Koch Theater and the American Museum of Natural History’s David H. Koch Dinosaur Wing were accordingly named after him in light of his major contributions.

“The significance of David’s generosity is best captured in the words of Adam Smith, who wrote, ‘to indulge our benevolent affections, constitutes the perfection of human nature,'” Charles said.

David Koch is also survived by his wife, Julia, and their three children.

“While we mourn the loss of our hero, we remember his iconic laughter, insatiable curiosity, and gentle heart,” Julia Koch said in a statement.

“His stories of childhood adventures enlivened our family dinners; his endless knowledge rendered him our ‘walking Google.’ His sensitive heart had him shed a tear at the beauty of his daughter’s ballet, and beam with pride when his son beat him at chess,” she wrote. “We will miss the fifth link in our family.”