Several (8) military conflicts are considered English civil wars:
Rebellion of 1088 to 1091 – in England and Normandy, The Rebellion of 1088 occurred after the death of William the Conqueror and concerned the division of lands in the Kingdom of England and the Duchy of Normandy between his two sons William Rufus and Robert Curthose. Hostilities lasted from 3 to 6 months starting around Easter of 1088.
The Anarchy (1135–54) – in England, The Anarchy was a civil war in England and Normandy between 1135 and 1154, which resulted in a widespread breakdown in law and order. The conflict began with a succession crisis towards the end of the reign of Henry I, when the king's only legitimate son, William Adelin, died aboard the White Ship in 1120. Henry's attempts to install his daughter, the Empress Matilda, as his successor were unsuccessful and on Henry's death in 1135, his nephew Stephen of Blois seized the throne with the help of his brother, Henry, bishop of Winchester. Stephen's early reign was marked by fierce fighting with English barons, rebellious Welsh leaders and Scottish invaders. Following a major rebellion in the south-west of England, Matilda invaded in 1139 with the help of her half-brother, Robert of Gloucester.
First Barons' War (1215–17) – in England, The First Barons' War (1215–17) was a civil war in the Kingdom of England in which a group of rebellious barons, led by Robert Fitzwalter and supported by a French army under the future Louis VIII of France, made war on King John of England. The war resulted from the king's refusal to accept and abide by the Magna Carta he had sealed on 15 June 1215, and from the ambitions of the French prince, who dragged the war on after many of the rebel barons had made peace with John.
Second Barons' War (1264–67) – in England, The Second Barons' War (1264–67) was a civil war in England between the forces of a number of barons led by Simon de Montfort against Royalist forces led by Prince Edward (later Edward I of England), in the name of Henry III.
Despenser War (1321–22) – Baronial revolt against Edward II instigated by Marcher Lords in opposition to court favourite Hugh Despenser.
Wars of the Roses (1455–87) – in England and Wales; Richard III was the last English king to die in combat, The Wars of the Roses were a series of dynastic wars for the throne of England. They were fought between supporters of two rival branches of the royal House of Plantagenet, the houses of Lancaster and York. They were fought in several sporadic episodes between 1455 and 1487.
The English Civil War (1642–51) was a series of armed conflicts and political machinations between Parliamentarians ("Roundheads") and Royalists ("Cavaliers") in the Kingdom of England over, principally, the manner of its government. The first (1642–46) and second (1648–49) wars pitted the supporters of King Charles I against the supporters of the Long Parliament, while the third (1649–51) saw fighting between supporters of King Charles II and supporters of the Rump Parliament. The war ended with the Parliamentarian victory at the Battle of Worcester on 3 September 1651. The overall outcome of the war was threefold: the trial and execution of Charles I; the exile of his son, Charles II; and the replacement of English monarchy with, at first, the Commonwealth of England (1649–53) and then the Protectorate (1653–59) under Oliver Cromwell's personal rule. The monopoly of the Church of England on Christian worship in England ended. Constitutionally, the wars established the precedent that an English monarch cannot govern without Parliament's consent, although the idea of parliament as the ruling power of England was legally established as part of the Glorious Revolution in 1688.
Monmouth Rebellion (1685) – in England, The Monmouth Rebellion, also known as The Revolt of the West or The West Country rebellion, was an attempt to overthrow James II, who had become King of England, Scotland and Ireland upon the death of his elder brother Charles II on 6 February 1685.
