Henry II (5 March 1133 – 6 July 1189), also known as Henry Curtmantle (French: Court-manteau), Henry FitzEmpress or Henry Plantagenet, ruled as King of England, Duke of Normandy and Aquitaine, Count of Anjou, Maine, and Nantes; at various times, he also partially controlled Scotland, Wales and the Duchy of Brittany. Before he was 40 he controlled England, large parts of Wales, the eastern half of Ireland and the western half of France—an area that would later come to be called the Angevin Empire.

Henry was the son of Geoffrey of Anjou and Matilda, daughter of Henry I of England. He became actively involved by the age of 14 in his mother's efforts to claim the throne of England, then occupied by Stephen of Blois, and was made Duke of Normandy at 17. He inherited Anjou in 1151 and shortly afterwards became the Duke of Aquitaine by marrying Eleanor of Aquitaine, whose marriage to Louis VII of France had recently been annulled. Stephen agreed to a peace treaty after Henry's military expedition to England in 1153, and Henry inherited the kingdom on Stephen's death a year later. Henry was an energetic and sometimes ruthless ruler, driven by a desire to restore the lands and privileges of his grandfather Henry I. During the early years of his reign the younger Henry restored the royal administration in England, re-established hegemony over Wales and gained full control over his lands in Anjou, Maine and Touraine. Henry's desire to reform the relationship with the Church led to conflict with his former friend Thomas Becket, the Archbishop of Canterbury. This controversy lasted for much of the 1160s and resulted in Becket's murder in 1170. Henry soon came into conflict with Louis VII and the two rulers fought what has been termed a "cold war" over several decades. Henry expanded his empire, often at Louis' expense, taking Brittany and pushing east into central France and south into Toulouse; despite numerous peace conferences and treaties, no lasting agreement was reached.

Henry and Eleanor had eight children—three daughters and five sons. Three of his sons would be king, though Henry the Young King was named his father's co-ruler rather than a stand-alone king. As the sons grew up, tensions over the future inheritance of the empire began to emerge, encouraged by Louis and his son King Philip II. In 1173 Henry's heir apparent, "Young Henry", rebelled in protest; he was joined by his brothers Richard (later a king) and Geoffrey and by their mother, Eleanor. France, Scotland, Brittany, Flanders, and Boulogne allied themselves with the rebels. The Great Revolt was only defeated by Henry's vigorous military action and talented local commanders, many of them "new men" appointed for their loyalty and administrative skills. Young Henry and Geoffrey revolted again in 1183, resulting in Young Henry's death. The Norman invasion of Ireland provided lands for his youngest son John (later a king), but Henry struggled to find ways to satisfy all his sons' desires for land and immediate power. By 1189, Young Henry and Geoffrey were dead, and Philip successfully played on Richard's fears that Henry II would make John king, leading to a final rebellion. Decisively defeated by Philip and Richard and suffering from a bleeding ulcer, Henry retreated to Chinon castle in Anjou. He died soon afterwards and was succeeded by Richard.

Henry's empire quickly collapsed during the reign of his son John, but many of the changes Henry introduced during his long rule had long-term consequences. Henry's legal changes are generally considered to have laid the basis for the English Common Law, while his intervention in Brittany, Wales, and Scotland shaped the development of their societies and governmental systems. Historical interpretations of Henry's reign have changed considerably over time. In the 18th century, scholars argued that Henry was a driving force in the creation of a genuinely English monarchy and, ultimately, a unified Britain. During the Victorian ex