Plantagenet Dynasty (1154-1399) After Stephen died, Henry I's grandson succeeded to the throne and was called Henry II. He was originally the Earl of Anjou in France, and his coat of arms had the pattern of plantagenet, hence the name Dynasty. The Hundred Years' War between Britain and France broke out in this dynasty. This dynasty lasted for eight generations, including King John 1 154, and Henry II began to rule the Plantagenet dynasty. The Plantagenet Dynasty (Anjou Dynasty) was the first golden age in British history, and a large number of famous kings emerged. Henry II, with high legal attainments, carried out many fruitful reforms in the British legal system. After his son Richard I succeeded to the throne, he took part in the Third Crusade, once defeated Saladin and became famous, and won the title of "Lion Heart King". John, Richard I's younger brother, succeeded to the throne and was defeated by Philip II, king of France, and lost a large territory in France. However, the Magna Carta of Freedom signed in 12 15 under the coercion of big noble is a milestone in the history of world constitutional development. During his reign, Henry III, the son of Landless King, was also coerced by big noble to pass the Oxford and Westminster Ordinances and open the Legislative Assembly. During the reign of Henry III's son "Long Legs" Edward I of England in England, the parliamentary system was mature and the British legal system was perfect. It also annexed Wales and made an expedition to Scotland, which laid the foundation for the unification of Britain. When Edward I of England's grandson Edward III arrived in England, the battle for the French throne began the Hundred Years' War between Britain and France, and the French knights were defeated several times. Edward III's grandson Richard II was deposed by Henry IV, Duke of Lancaster, and the Plantagenet Dynasty was replaced by Lancaster Dynasty.