David Koch — the billionaire co-owner of Koch Industries and powerful political donor — has died. He was 79 years old.

The death of the billionaire conservative icon, who stepped down from his role as executive vice president of the family’s company last year, was announced Friday morning by his older brother, Charles.

“It is with a heavy heart that I announce the passing of my brother David. Anyone who worked with David surely experienced his giant personality and passion for life,” Charles said in a statement.

David was diagnosed with advanced prostate cancer 27 years ago and given just a few years to live — but wound up beating those odds, Charles added.

“David liked to say that a combination of brilliant doctors, state-of-the-art medications and his own stubbornness kept the cancer at bay,” Charles’ statement continued. “We can all be grateful that it did, because he was able to touch so many more lives as a result.”

Last year, Charles said he was “deeply saddened” over his brother’s retirement due to his declining health.

“David has always been a fighter and is dealing with this challenge in the same way,” the letter said.

The Koch brothers are regarded as some of the biggest players in conservative politics.

The two founded the powerful conservative group Americans for Prosperity and have pumped hundreds of millions of dollars backing GOP members at all levels of government, much to the dismay of the opposition party.

David joined Koch Industries in 1970 and was the 11th richest man in the world with a net worth of $50.5 billion, according to Forbes. His brother is worth the same amount.

Koch Industries, co-founded by the Koch brothers’ father in 1940, is the second-wealthiest private firm in the country with annual revenues estimated as high as $110 billion.

David is survived by his wife, Julia Flesher, and their three children. In their own statement, the family remembered the philanthropist as their “walking Google.”

“While we mourn the loss of our hero, we remember his iconic laughter, insatiable curiosity, and gentle heart,” the statement said. “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. We will miss the fifth link in our family.”

The circumstances surrounding David’s death weren’t immediately clear.

The Koch brothers have drawn the ire over the years of Democrats for their right-wing influence.

But the pair has shown resistance to the Trump administration, with their political network famously refusing to endorse a candidate in the 2016 presidential election.

Leading up to that election, Charles told ABC’s “This Week” that he was disgusted by all of the candidates.

“You’re role models and you’re terrible role models. So how — I don’t know how we could support them,” he said.

Besides spending millions of dollars backing an array of GOP candidates and causes, David had his own foray into politics.

He ran as a vice presidential candidate in 1980 under the Libertarian Party. He received just 1% of the vote.

David earned an engineering degree from MIT. Some of philanthropy highlights include a $100 million donation to his alma mater for the creation of the David H. Koch Institute for Integrative Cancer Research.

He also donated $15 million to The Smithsonian’s National Museum of Natural History, who in turn named a wing dedicated to the story of human evolution after him.