John, also known as John Lackland (Norman French: Johan sanz Terre), was King of England from 6 April 1199 until his death in 1216. John lost the Duchy of Normandy to King Philip II of France, resulting in the collapse of most of the Angevin Empire and contributing to the subsequent growth in power of the Capetian dynasty during the 13th century. The baronial revolt at the end of John's reign led to the sealing of Magna Carta, a document sometimes considered to be an early step in the evolution of the constitution of the United Kingdom.
John, the youngest of five sons of King Henry II of England and Eleanor of Aquitaine, was at first not expected to inherit significant lands. Following the failed rebellion of his elder brothers between 1173 and 1174, however, John became Henry's favourite child. He was appointed the Lord of Ireland in 1177 and given lands in England and on the continent. John's elder brothers William, Henry and Geoffrey died young; by the time Richard I became king in 1189, John was a potential heir to the throne. John unsuccessfully attempted a rebellion against Richard's royal administrators whilst his brother was participating in the Third Crusade. Despite this, after Richard died in 1199, John was proclaimed King of England, and came to an agreement with Philip II of France to recognise John's possession of the continental Angevin lands at the peace treaty of Le Goulet in 1200.
When war with France broke out again in 1202, John achieved early victories, but shortages of military resources and his treatment of Norman, Breton and Anjou nobles resulted in the collapse of his empire in northern France in 1204. John spent much of the next decade attempting to regain these lands, raising huge revenues, reforming his armed forces and rebuilding continental alliances. John's judicial reforms had a lasting impact on the English common law system, as well as providing an additional source of revenue. An argument with Pope Innocent III led to John's excommunication in 1209, a dispute finally settled by the king in 1213. John's attempt to defeat Philip in 1214 failed due to the French victory over John's allies at the battle of Bouvines. When he returned to England, John faced a rebellion by many of his barons, who were unhappy with his fiscal policies and his treatment of many of England's most powerful nobles. Although both John and the barons agreed to the Magna Carta peace treaty in 1215, neither side complied with its conditions. Civil war broke out shortly afterwards, with the barons aided by Louis of France. It soon descended into a stalemate. John died of dysentery contracted whilst on campaign in eastern England during late 1216; supporters of his son Henry III went on to achieve victory over Louis and the rebel barons the following year.