Warren Buffett and Bill Gates met on 4th of July weekend 30 years ago. Here's how their iconic friendship began.

• Warren Buffett and Bill Gates first met 30 years ago on Fourth of July weekend.
• The investor and the Microsoft cofounder expected to have little in common.
• Buffett and Gates became close friends and philanthropic partners.

Warren Buffett and Bill Gates are very close friends who have partnered in philanthropy, political activism, and online bridge. Their iconic friendship began almost 30 years to the day on Fourth of July weekend, 1991.

Buffett was visiting Meg Greenfield, a Washington Post editor based in Washington state at the time, he recalled at Berkshire Hathaway's annual meeting in 2000. Greenfield was friends with Gates' parents, so she took Buffett down to visit them. Gates initially had no interest in meeting Buffett as he had little respect for the investor's livelihood.

"I didn't even want to meet Warren because I thought, 'Hey, this guy buys and sells things, and so he found imperfections in terms of markets - that's not value added to society, that's a zero-sum game that is almost parasitic.' That was my view before I met him … he wasn't going to tell me about inventing something," Gates said at a conference in 2019.

However, Gates changed his mind after Buffett began peppering him with "amazingly good questions that nobody had ever asked," he recalled in a 2016 blog post.

Buffett wasn't thrilled to meet Gates either, but he quickly warmed to the Microsoft cofounder.

"We hit it off immediately," the investor said in 2000. "We had a great time. He had this chimpanzee to whom he was going to try and explain this technical stuff. But I was kind of an interesting chimpanzee to him, and he's a terrific teacher."

The fateful meeting ultimately led to Buffett pledging in 2006 to give virtually all of his wealth to the Bill & Melinda Gates Foundation and four other foundations. He reached the halfway mark towards that goal last month, and decided it was the right time to resign as a trustee of the Gates Foundation.

Buffett and Gates have engaged in plenty of antics over the past three decades, from competing in newspaper-tossing and table-tennis competitions, to buying lunch at McDonald's with coupons and picking up a shift at Berkshire-owned Dairy Queen. Gates also baked a cake to celebrate Buffett's 90th birthday last fall.

Given their special bond, both billionaires must be very happy that they didn't skip that Fourth of July gathering 30 years ago.