Trial by combat (also wager of battle, trial by battle or judicial duel) was a method of Germanic law to settle accusations in the absence of witnesses or a confession in which two parties in dispute fought in single combat; the winner of the fight was proclaimed to be right. In essence, it was a judicially sanctioned duel. It remained in use throughout the European Middle Ages, gradually disappearing in the course of the 16th century.

Ashford v Thornton (1818) 106 ER 149 is an English law case in the Court of King's Bench which upheld the right of the defendant to trial by battle on a private appeal from an acquittal for murder.

In 1817, Abraham Thornton was charged with the murder of Mary Ashford. Thornton had met Ashford at a dance and had walked with her from the event. The next morning, she was found drowned in a pit with little evidence of violence. Public opinion was heavily against Thornton, but the jury quickly acquitted him and found him not guilty of rape.

Mary's brother William Ashford launched an appeal, and Thornton was rearrested. Thornton claimed the right to trial by battle, a medieval usage that had never been repealed by Parliament. Ashford argued that the evidence against Thornton was overwhelming and that he was thus ineligible to wage battle.

The court decided that the evidence against Thornton was not overwhelming, and that therefore trial by battle was a permissible option under law. Ashford declined the offer of battle, however, and therefore Thornton was freed from custody. Appeals such as Ashford's were abolished by statute in 1819, and with them the right to trial by battle. Thornton emigrated to the United States.