Tom Sayers was an English bare-knuckle prize fighter. There were no formal weight divisions at the time, and although Sayers was only five feet eight inches tall and never weighed much more than 150 pounds, he frequently fought much bigger men. In a career which lasted from 1849 until 1860, he lost only one of sixteen bouts. He was recognized as heavyweight champion of England between 1857, when he defeated William Perry and his retirement in 1860.
Tom Sayers, champion of England, and his battles (from the Police Gazette)
Sayers's 1859 letter accepting Heenan's challenge
The Champion Fight between Heenan and Sayers on the 17th April, 1860. From a sketch on the spot by Thomas Nast, engraved by A.V.S. Anthony, on board the Vanderbilt, on her return passage, for the New York Illustrated News
Retired boxer Jem Ward painted this picture of the Sayers–Heenan fight.
Bare-knuckle boxing is a full-contact combat sport based on punching without any form of padding on the hands. The sport as it is known today originated in 17th-century England and differs from street fighting as it follows an accepted set of rules.
Irish-American fighter John L. Sullivan
Tom Molineaux (left) vs Tom Cribb in a re-match for the heavyweight championship of England, 1811.