Oral history: First torrent was uploaded circa 2002 by Bram Cohen's brother. It was a video of his metal band playing live.

But BitTorrent really took off when redhat played this dirty trick: their distro was free to distribute but you had to pay to download it. (free as in free speech, not as in free beer). Bram paid to download it and made it available with BitTorrent. The torrent of the iso kept running for more than a year with thousands of downloads. BitTorrent was alive.

Soon BitTorrent represented 30% of all internet traffic and was the primary reason to get xDSL internet access.

Before writing BitTorrent, Bram worked on a project named mojonation, when released it was slashdotted and didn't stand the load. Bram learned from this experiment and wrote BitTorrent in ~6 months.

(source: I met Bram Cohen + p2phackers mailing list)