Henry II of England vs Kaidu

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.

Kaidu, grandson of Ogedei, launched a rebellion against Kublai Khan, challenging his authority as Great Khan. He claimed the Ogedeid line had the rightful claim to the throne, initiating a decades-long conflict in Central Asia.

Kaidu's forces fought Kublai's army at the Talas River in Central Asia. The battle was indecisive but established Kaidu as the dominant power in the region, controlling much of the former Chagatai Khanate.

Kaidu died from wounds sustained in a battle against the Yuan dynasty near the Altai Mountains. His death ended the major rebellion against Kublai's successors, though his sons continued resistance for a time.