"The exercising of weapons putteth away aches, griefs, and diseases, it increaseth strength and sharpeneth the wits, it giveth a perfect judgment, it expelleth melancholy, choleric, and evil conceits, it keepeth a man in breath, in perfect healthe, and long life." – George Silver (1599)

From Gentlemen’s Blood by Barbara Holland

AGAINST

In France, a splendid duel was fought in 1400 between a suspected murderer and his accuser, a dog. The Chevalier Maquer killed Aubrey de Montdidier in the Forest of Bondy, near Paris, and buried the body. The only witness was Montdidier’s greyhound.
The dog went back to town to a friend of his master’s and led the friend to the spot, where he whined and scratched the ground. The body was recovered and reburied, and the greyhound moved in with the friend. Shortly thereafter, it met up with Maquer and attacked him viciously; three men had to pull it off him. The dog was an otherwise gentle and amiable sort, but it kept on flying at Maquer whenever it saw him.

This was reported to the king, who decided it was definitely an accusation and arranged for the single-combat trial. The fight took place on the He de France in Paris, Maquer with a lance, the greyhound with its natural weapons. The dog sprang on the man with amazing ferocity and clamped its teeth around his throat and couldn’t be shaken off. Maquer screamed that he’d confess if they’d pull off the dog.

This, in contemporary eyes, proved the justice of combat trials pretty conclusively, and Maquer was hanged and strangled on the gibbet at Montfaucon.

VIA

[In the face of laws prohibiting dueling...s]ome few, even in the face of the strict new laws, managed to fight anyway. In India in 1894, two British colonial officers, Captain Phillips and Lieutenant Shepherd, suffered a falling-out and contrived an exotic local variation on the duel. They locked a deadly venomous snake, probably a cobra, into a dark room, waited an hour, and then entered the room from opposite doorways, groping their way blindly around the furniture. After ten minutes, Lieutenant Shepherd screamed. Phillips, they say, rushed out of the room with his hair turned instantly white; Shepherd died gruesomely a few hours later.