First Barons' War

First Barons' War
Part of the Capetian–Plantagenet rivalry
King John of England (left) in battle with the troops of Louis of France (right)
Date 1215–1217 Location England Result Tactical victory for the English monarchy Strategical victory for the Barons of England Treaty of Lambeth Restoration of Magna Carta
Belligerents
Kingdom of England	Army of God and Holy Church Kingdom of France Supported by: Kingdom of Scotland
Commanders and leaders
King John # Hubert de Burgh William Longespée Ranulf de Blondeville Peter des Roches William de Ferrers William Marshal (from March 1217)	Prince Louis of France Robert, Lord of Champignelles Robert Fitzwalter Saer de Quincy Gilbert de Clare Henry de Bohun William Marshal (until March 1217) Thomas, Count of Perche † Eustace the Monk

The First Barons' War (1215–1217) was a civil war in the Kingdom of England in which a group of rebellious major landowners (commonly referred to as barons) led by Robert Fitzwalter waged war against King John of England. The conflict resulted from King John's disastrous wars against King Philip II of France, which led to the collapse of the Angevin Empire, and John's subsequent refusal to accept and abide by Magna Carta, which John had sealed on 15 June 1215.

The rebellious barons, faced with an uncompromising king, turned to King Philip's son, Louis, who, in 1216, then sailed to England with an army despite his father's disapproval, as well as the pope's, who subsequently excommunicated him. Louis captured Winchester and soon controlled over half of the English kingdom.^[1] He was proclaimed "King of England" in London by the barons, although never actually crowned.

Louis's ambitions of ruling England faced a major setback in October 1216, when John's death led to the rebellious barons deserting him in favour of John's nine-year-old son, Henry III, and the war dragged on. Louis's army was finally beaten at the Battle of Lincoln on 20 May 1217. Also, after a fleet assembled by his wife, Blanche of Castile, attempted to bring him French reinforcements but was defeated off the coast of Sandwich on 24 August 1217, he was forced to make peace on English terms. He signed the Treaty of Lambeth and surrendered the few remaining castles that he held. The treaty had the effect of Louis agreeing he had never been the legitimate king of England. That formalised the end of the civil war and the departure of the French from England.^[2]