The Mutiny Acts were an almost 200-year series of annual Acts passed by the Parliament of England, the Parliament of Great Britain, and the Parliament of the United Kingdom for governing, regulating, provisioning, and funding the English and later British Army.
The first Mutiny Act was passed in 1689 in response to the mutiny of a large portion of the army which stayed loyal to James II upon William III taking the crown of England. Today, mutiny by British forces is punished under the Armed Forces Act 2006.
Depending on events, additions, and changes within the established system more than one Mutiny Act might be passed within a given year. Within the empire specific geographical disturbances were sometimes governed by specific acts, such as the Mutiny, East Indies Act 1754 (27 Geo. 2 c. 9), or the Mutiny, America Act from 1765 (5 Geo. 3 c. 33) to 1776 (16 Geo. 3 c. 11). A closely related series of Marine Mutiny Acts starting in 1755 (28 Geo. 2 c. 11) would regulate his Majesty's marine forces while on shore, and continue well into the 19th century.
During the Middle Ages, European rulers applied the same laws to both civilian and military populations. Because of this, military law (law governing armed forces) and martial law (control of society by the military) were not independent legal approaches. Rulers began separating the laws governing the civilian population and the laws for the armed forces as the medieval period drew to a close.
In England, William the Conqueror's Aural Regis (or King's Court) assisted him in ruling both his armed forces and the English population. Over time, this court divided and developed specialized legal expertise. King Edward I created a Court of Chivalry headed by the Lord High Constable and the Earl Marshall, two members of the King's Court. This Court of Chivalry was given authority over cases of military law, chivalry, heraldry, and murder or high treason overseas. The army was seen as the crown's personal force. Its governance, as a military force, was the crown's royal prerogative. The crown governed the military by publishing articles of war. These articles applied to the army during a specific war or campaign. The Court of Chivalry assisted the crown by preparing these articles and enforcing them. Therefore, military law could and would change depending on the campaign or war. Although harsh, the articles were clear in their expectations for military personnel.