In England, the High Middle Ages spanned the period from the Norman Conquest in 1066 to the death of King John, considered by some historians to be the last Angevin king of England, in 1216.

A disputed succession and victory at the Battle of Hastings led to the conquest of England by William of Normandy in 1066. This linked the Kingdom of England with Norman possessions in the Kingdom of France and brought a new aristocracy to the country that dominated landholding, government and the church. They brought with them the French language and maintained their rule through a system of castles and the introduction of a feudal system of landholding. By the time of William's death in 1087, England formed the largest part of an Anglo-Norman empire. William's sons disputed succession to his lands, with William II emerging as ruler of England. On his death in 1100 his younger brother claimed the throne as Henry I and defeated his brother Robert to reunite England and Normandy. Henry was a ruthless yet effective king, but after the death of his only male heir William Adelin, he persuaded his barons to recognise his daughter Matilda as heir. When Henry died in 1135 her cousin Stephen of Blois had himself proclaimed king, leading to a civil war known as The Anarchy. Eventually Stephen recognised Matilda's son Henry as his heir and when Stephen died in 1154, he succeeded as Henry II.

Henry had extensive holdings in France and asserted his authority over Wales, Scotland and Ireland. He clashed with his appointee to the Archbishopric of Canterbury, Thomas Becket, resulting in Becket's murder. The later part of his reign was dominated by rebellions involving his sons and Philip II of France that forced him to accept his son Richard as sole heir. Richard acceded to the Angevin inheritance on Henry's death in 1189 and almost immediately departed on a Crusade. On his return he was taken hostage in Germany and a huge ransom was paid in order to secure his release in 1194. He spent the remainder of his reign restoring his French lands, dying in 1199. His younger brother John succeeded in England and fought a successful war against Richard's nephew Arthur for control of the French domains. John's behaviour led to rebellions by the Norman and Angevin barons that dwindled his control of the continental possessions. His attempt to retake Normandy and Anjou failed at the Battle of Bouvines. This weakened his position in England, eventually resulting in the treaty called Magna Carta, which limited royal power, and the First Barons' War. His death in 1216 is considered by some historians to mark the end of the Angevin period and the beginning of the Plantagenet dynasty.

The Normans adopted many Anglo-Saxon governmental institutions, but the feudal system concentrated more power in the hands of the monarch and a small elite. The rights and roles of women became more sharply defined. Noblewomen remained significant cultural and religious patrons and played an important part in political and military events. During the twelfth century divisions between conquerors and the English began to dissolve and they began to consider themselves superior to their Celtic neighbours. The conquest brought Norman and French churchmen to power. New reformed religious and military orders were introduced into England. By the early thirteenth century the church had largely won its argument for independence from the state, answering almost entirely to Rome. Pilgrimages were a popular religious practice and accumulating relics became important for ambitious institutions. England played a prominent role in the Second, Third and Fifth Crusades.

Between the ninth and thirteenth centuries England experienced the Medieval Warm Period, a prolonged period of warmer temperatures that allowed poorer land to be brought into cultivation. Agricultural land became typically organised around manors. By the eleventh century, a market economy was flourishing across much of England, while the eastern and southern towns were heavily involved in international trade. Many hundreds of new towns, some of them planned communities, were built, supporting the creation of guilds and charter fairs. Anglo-Norman warfare was characterised by attritional military campaigns of raids and seizure of castles. Naval forces enabled the transportation of troops and supplies, raids into hostile territory and attacks on enemy fleets. After the conquest the Normans built timber motte and bailey and ringwork castles in large numbers, which were replaced by stone buildings from the twelfth century. The period has been used in a wide range of popular culture, including William Shakespeare's plays.

In 1002 King Æthelred II of England married Emma, the sister of Richard II, Duke of Normandy. Their son Edward the Confessor, who spent many years in exile in Normandy, succeeded to the English throne in 1042. This led to the establishment of a powerful Norman interest in English politics, as Edward drew heavily on his former hosts for support, bringing in Norman courtiers, soldiers, and clerics and appointing them to positions of power, particularly in the Church. Childless and embroiled in conflict with the formidable Godwin, Earl of Wessex, and his sons, Edward may also have encouraged Duke William of Normandy's ambitions for the English throne.

When King Edward died at the beginning of 1066, the lack of a clear heir led to a disputed succession in which several contenders laid claim to the throne of England. Edward's immediate successor was the Earl of Wessex, Harold Godwinson, the richest and most powerful of the English aristocrats. Harold was elected king by the Witenagemot of England and crowned by the Archbishop of York, Ealdred, although Norman propaganda claimed the ceremony was performed by Stigand, the uncanonically elected Archbishop of Canterbury. Harold was immediately challenged by two powerful neighbouring rulers. Duke William claimed that he had been promised the throne by King Edward and that Harold had sworn agreement to this. King Harald III of Norway, commonly known as Harald Hardrada, also contested the succession. His claim to the throne was based on an agreement between his predecessor Magnus I of Norway and English King Harthacnut, whereby if either died without heir the other would inherit both England and Norway. William and Harald at once set about assembling troops and ships to invade England. Tostig Godwinson, brother of Harold, made a series of attacks in the north of England in early 1066 that may have been the beginning of a bid for the throne, but after defeat at the hands of Edwin and Morcar and the desertion of most of his followers he threw his lot in with Harald Hardrada, who invaded northern England in early September. Harold defeated and killed Hardrada and Tostig at the battle of Stamford Bridge. William invaded with an army of Norman followers and mercenaries. Harold marched south to meet him but was defeated and killed at the battle of Hastings on 14 October, and William's forces rapidly occupied the south of England.

Major revolts followed, which William suppressed before intervening in the north-east of England, establishing Norman control of York and devastating the region. Once England had been conquered, the Normans faced many challenges in maintaining control. They were few in number compared to the native English population; including those from other parts of France, historians estimate the number of Norman settlers at around 8,000. William's followers expected and received lands and titles in return for their service in the invasion, but William claimed ultimate possession of the land in England over which his armies had given him de facto control, and asserted the right to dispose of it as he saw fit. Henceforth, all land was "held" directly from the king in feudal tenure in return for military service. A Norman lord typically had properties located in a piecemeal fashion throughout England and Normandy, and not in a single geographic block.