Warren Buffett and Bill Gates first met at a 4th of July celebration. Here's how they became billionaire buddies.

• Warren Buffett and Bill Gates were introduced to each other at a Fourth of July celebration in 1991.
• The legendary investor and the Microsoft cofounder expected to have little in common.
• Yet Buffett and Gates hit it off and became close friends and philanthropic partners.

Warren Buffett and Bill Gates might be the best-known billionaire buddies on the planet. Their famous friendship began over three decades ago 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 zero interest in meeting Buffett as he had little respect for investors.

"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 excited to meet Gates either. The tech entrepreneur, 25 years his junior, interested Buffett "mainly because he was known to be brilliant and because the two of them were neck-and-neck in the Forbes race," author Alice Schroeder writes in "The Snowball: Warren Buffett and the Business of Life." However, "computers looked like Brussels sprouts to Buffett; no, he did not want to try them this once," she noted.

Even so, Buffett quickly warmed to the Microsoft cofounder.

"We hit it off immediately," the Berkshire CEO 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."

"We talked and talked and talked and talked and paid no attention to anybody else. I started asking him a whole bunch of questions about his business, not expecting to understand any of it. He's a great teacher, and we couldn't stop talking," he told Schroeder.

The unwanted 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. Since then, he has donated over half of his Berkshire shares, representing well over $50 billion worth of giving. 

"Warren's generosity plays an enormous role in achieving the foundation's ambitious goals and has made an impact on millions of lives," Gates tweeted in 2023. "I always find it hard to adequately express how much our lifelong friendship and his support means to me."

Buffett and Gates have maintained a playful relationship for over 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 in August 2020.

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