Henry II of England

Henry II clashed with Thomas Becket, the Archbishop of Canterbury, over the rights of the church versus the crown. The conflict culminated in Becket's murder in Canterbury Cathedral in 1170. Henry was widely blamed for the murder, leading to a crisis of legitimacy.

Henry II issued the Assize of Clarendon, which established a system of royal justice and standardized legal procedures across England. This reform laid the foundation for English common law, replacing local customs with a unified legal system. It strengthened royal authority and reduced the power of feudal courts.

Henry II signed the Treaty of Montmirail with King Louis VII of France. The treaty temporarily ended hostilities between England and France. It also arranged the marriage of Henry's son Richard to Louis's daughter, but the peace was short-lived.

Henry II led an expedition to Ireland, asserting English control over the island. He received the submission of many Irish kings and established English rule. This conquest began centuries of English involvement in Ireland, leading to long-term conflict.

Henry II's sons, Henry the Young King, Richard, and Geoffrey, rebelled against him with support from King Louis VII of France. The revolt lasted over a year and was eventually suppressed. It highlighted the tensions within the Plantagenet family and weakened Henry's authority.