King Henry II was the King of England from 1154 to 1189. He is known for establishing the Plantagenet dynasty and for his efforts to reform the legal system, which laid the groundwork for common law. His reign marked a significant expansion of royal power and territorial control, including parts of France. Henry II was also the father of several notable children, including Richard the Lionheart and John Lackland. His conflicts with the church, particularly with Thomas Becket, the Archbishop of Canterbury, highlighted the struggle between royal authority and ecclesiastical power during his reign.