John, King of England

King John's funeral effigy,
Worcester Cathedral

King John, also known as John Lackland due to a joke made by his father in John's childhood, was the ruler of the kingdom of England for seventeen years, from his ascension to the throne in 1199 to his death in 1216. He was born the youngest of the five sons of King Henry II; yet with three of his older brothers dying young, John became a potential heir to his brother Richard's throne. Sensing this, John attempted a rebellion against his brother while Richard was fighting in the Third Crusade. This rebellion failed, but nevertheless when Richard died in 1199, John was proclaimed king and met with King Phillip II of France to establish his legitimacy. 

Soon after his recognition, John became famous for losing wars with France, resulting in the loss of all lands in Normandy and on the European mainland. An argument between King John and Pope Innocent III in 1209 led to John's excommunication from the Catholic Church. After settling the disagreements in 1213, John attempted to recapture the lands of Normandy just a year later, losing once again to Phillip II. At the same time, Innocent III declared that any person with a claim to seize the throne of England from John would be (at least in the view of the Church) legally entitled to do so. This was simply too much for the barons of England, who rebelled and forced John to sign the Magna Carta in 1215. This gave the people of England certain rights that the king could not renege on. However, John was used to a certain freedom of governance as he saw fit, and attempted to remove these restrictions by removing the barons that created them. Civil war broke out, and the fighting soon descended into a stalemate. In 1216, John contracted dysentery while on the march and soon died. His son, Henry III, succeeded him and would rule England for most of the thirteenth century.

Sources:
http://en.wikipedia.org/wiki/John,_King_of_England
http://www.historylearningsite.co.uk/king_john.htm