Trial by battle, or "wager of battel," was a legal procedure used in appeals of felony, certain civil cases, and affairs of chivalry to settle disputes by combat. It arose in societies where individuals took the law into their own hands. Analogous to the battle between King David and Goliath, where national destinies depended on single combat, trial by battle relied on the belief that God would favor the righteous cause.

The practice was customary among ancient Germans, Norsemen, and was first written into law by the Burgundians around A.D. 501. Judicial duels were also common among the Goths, Swedes, Russians, Hungarians, Almains, and Normans. In England, William the Conqueror introduced trial by battle for military, criminal (appeals of felony), and civil (writ of right) cases.

Rules and procedures existed for these combats, including oaths against sorcery. In civil cases, champions often fought with batons, while in treason cases, swords and spears were used.

Trial by battle gradually declined in England, with legislation under Edward III favoring trial by jury. Exemptions from battle were granted to certain individuals like women, priests, and the elderly. The last recognized case was in 1818 (Ashford vs. Thornton), which led to its abolition in 1819.

Trial by battle has been a recurring theme in English literature, from the Song of Roland to the works of Shakespeare and Sir Walter Scott. This "ancient mode of trial" was ultimately replaced by the "fairer method of jury trial".