Prize fights have not always ended after 12 or 15 rounds. Also known as bare-knuckle boxing because fighters did not originally wear gloves, prize fighting dates back to the late 1600s and up until 1900, prize fights were permitted to last up to 100 rounds. Prize fighting then lacked safety equipment and had more lax rules of conduct and weight classification. The matches were permitted to last until one fighter was knocked out or severely injured and unable to continue, and fighters could be hit while down. In the mid-1800s, the industry began reforming rules, including adding weight classification, requiring padded gloves, and limiting rounds to 15.
More about the history of boxing:
The 1719 prize fighting Champion of England, James Figg, retained the title for 15 years and lost just one fight in his career.
Although boxing was included in the ancient Olympic Games in 7th century BC, it did not become an official event in the modern Olympics until 1904.
Prize fighter Jack Broughton was buried at Westminster Abbey after his death in 1789, but his request for his headstone to read “Champion of England” was not granted until 1988.