Henry Plantagenet, also known as Henry II of England, was born in 1133 and became king in 1154. He was the first monarch of the Plantagenet dynasty and ruled until his death in 1189. Henry is known for his significant legal reforms, which laid the groundwork for the English common law system. Henry II's reign was marked by conflicts with his sons and disputes with the church, particularly with Thomas Becket, the Archbishop of Canterbury. His efforts to consolidate power and expand his territories included parts of France, making him one of the most powerful rulers of his time.