In the 5th century, when England had only recently been deserted by the Roman legions, the Anglo-Saxons established the independent kingdoms of Northumbria, Mercia, Wessex, Kent, Essex, Sussex and East Anglia, which were collectively known as the Heptarchy. During the 6th and 7th centuries, the Anglo-Saxon kingdoms engaged in heroic battles for military supremacy and were gradually converted to Christianity. After Augustine's mission in the late 6th century, English Christianity was consolidated. In the 8th century, the Anglo-Saxons were violently attacked and devastated by the Vikings and by the 9th century, the Vikings sporadic forays into England became a recurring harassment. Also during the 9th century, the country was divided between the four rival kingdoms of Northumbria, Mercia, East Anglia and Wessex, which were later unified by Egbert, King of Wessex.
In 994, the Danes invaded England, and this invasion eventually led to the expulsion of the Anglo-Saxon King Ethelred. Ethelred fled to Normandy, where his family remained until 1042, and the Anglo-Saxon rulers never truly recovered their lost power. After 1042, a Danish dynasty of kings ruled, and then Edward the Confessor, son of Ethelred, came to the throne. Upon the death of Edward in 1066, the elected king was challenged by Duke William of Normandy. William's successful invasion of 1066, known as the Norman Conquest, ushered in the reign of the Norman kings. The Norman Conquest from France and their victory at the Battle of Hastings, meant that many Anglo-Saxon landholders lost their property to Duke William and his invading nobles. However, despite this change of leadership, English culture remained predominantly Anglo-Saxon.
The early years of Norman rule were marked by rebellion and oppression. William sought to achieve political stability by centralizing authority upon the king and although learning was encouraged during William's reign, many of his policies were tyrannical in nature. Under this oppressive Norman rule many families decided to move north to Yorkshire and beyond the border to Scotland.
During the modern era, England was devastated by religious and political conflict. Under the Tudors the problems of succession, strife between Catholics and Protestants, and the fear of foreign invasion had mainly been resolved. Later, under the House of Stuart, there were conflicts between the king and parliament, and between the Catholics and the Protestants. The Stuarts came to power at a time when the middle class was becoming increasingly powerful and willing to assert its rights through parliament. The Stuarts were ousted from power first by Cromwell and then by the Glorious Revolution which resulted in the long series of Jacobite uprisings.