Charles (left) and David Koch (right). The Seminar Network via YouTube/Getty Images

Charles and David Koch have been titans of industry and politics for decades.

David, 79, has died, the family announced on Friday.

The company their father founded, now known as Koch Industries, is the second-largest company in the US with an annual revenue of $100 billion.

Libertarians who favor small government and few taxes, the Kochs have tangled with President Donald Trump, as they oppose many of his policies, including tariffs, the travel ban, and immigration.



The Koch network, started and led by billionaires Charles and David Koch, has played an instrumental role in the American political system over the last several decades.

David, 79, has died, the family announced on Friday.

The Koch brothers' influence in politics has been particularly felt in Republican and Libertarian circles, as the group has primarily raised money for conservative candidates who align with their political philosophies.

Their influence has only increased and become more scrutinized since the Citizens United Supreme Court decision in 2010, which allowed corporations to make an unlimited number of donations to candidates.

But the Koch network has shown an openness to supporting Democrats as it has slowly distanced itself from President Donald Trump and the GOP.

Here's how the Koch brothers became two of the most influential and politically active donors in modern history.