Raids by seaborne Scandinavian pirates on sites in Britain, especially largely undefended monastic sites, began at the end of the eighth century AD. By the end of the ninth century, there were large-scale settlements of Scandinavians in various parts of Britain, and they had achieved political domination over a significant territory. 

In 793 AD, an anguished Alcuin of York wrote to the Higbald, the bishop of Lindisfarne and to Ethelred, King of Northumbria, bemoaning the unexpected attack on the monastery of Lindisfarne by Viking raiders, probably Norwegians sailing directly across the North Sea to Northumbria.

It is clear from the letter that Lindisfarne was not destroyed. Alcuin suggested that further attack might be averted by moral reform in the monastery. Over the next few decades, many monasteries in the north were destroyed, and with them any records they might have kept of the raids. We know no historical details of the raids in Scotland, although they must have been extensive.

Iona was burnt in 802 AD, and 68 monks were killed in another raid in 806 AD. The remaining monks fled to Kells (County Meath, Ireland) with a gospel-book probably produced in Iona, but now known as the ‘Book of Kells’.

Other monasteries in Scotland and northern England simply disappear from the record. Lindisfarne was abandoned, and the monks travelled around northern England with their greatest possession, the relics of St. Cuthbert, until they found a home in Durham in 995 AD.

We cannot be sure of the impact the Vikings had on Scotland due to a real scarcity of written material from the area. But the surviving place names show us that the Orkneys and Shetlands, and the mainland of Caithness and Sutherland, were heavily settled by Norwegians.

Those Norwegians were probably involved in the greatest political upset in the north – the disappearance of the kingdom of the Celtic Picts. In the eighth century, the Picts had one of the most important kingdoms in Britain. By the end of the ninth century they had vanished. In their place was a kingdom of Scotland, controlled by the Scots, who were the descendents of immigrants from Ireland in the fifth and sixth centuries (the 
Scotti tribe).

The Scotti took advantage of the presence of the Vikings, and, above all, under King Kenneth MacAlpine, they did so with considerable aggression and intelligence. They promoted themselves as the kings of all those in northern Britain, or ‘Alba’.

They wove a new national history, which emphasised (or invented) many links between the Scottish and Pictish dynasties. They also promoted the idea that St. Columba, the founder of the monastery of Iona, was the apostle of all those in the north.

The Viking raids in England were sporadic until the 840s AD, but in the 850s Viking armies began to winter in England, and in the 860s they began to assemble larger armies with the clear intent of conquest.

In 865 AD, they forced the East Angles (Anglia) to help supply an army, which in 866 AD captured York, and in 867 AD, they took over the southern part of the kingdom of Northumbria.

The Viking leader, Hálfdan Ragnarsson led the Viking army to a conquest of Mercia in 874 AD, organised a parcelling out of land among the Vikings in Northumbria in 876 AD, and in 878 AD moved south and forced most of the population of Wessex to submit. 

The Vikings had conquered almost the whole of England.

King Alfred the Great hid in the marshes near Athelney (Somerset) in 878 AD, but then emerged, re-formed his army, and defeated the Vikings later that year at Edington (Wiltshire).

After the peace treaty Alfred forced on the Vikings, the Viking army moved across the Channel, giving the king some time to organise for war.

King Alfred built fortresses, established a defensive strategy, and built up a navy. By the time the Vikings returned in the 890s, the West Saxons were able to resist, leaving Alfred, at his death in 899 AD, king of the only independent English kingdom. We know more about him than about most early medieval kings in Britain. He ordered the compilation of the ‘Anglo-Saxon Chronicle’, a major source of  information that was continued as contemporary chronicles in various centres until the 12th century.

The great Welsh king Hywel Dda (Hywel the Good) was apparently a close ally. In fact, he was so Anglophile that he named one of his sons Edwin and sponsored a written law code after the English model.

Alfred was succeeded by his son Edward the Elder (899-924 AD) and grandson Æthelstan (924-939 AD). Both these rulers were, in many ways, even more important in the history of England than Alfred himself. In a few expeditions, Edward (with the direct military help of his sister Æthelflæd, widow of the Mercian king) conquered the south of England from the Danes and incorporated Mercia itself into his kingdom.

The ‘Anglo-Saxon Chronicle’ tells us that Edward built a fortress at Bakewell (Derbyshire), and there he was chosen ‘father and lord’ by the king of the Scots, the king of the Strathclyde Welsh, and the people of Northumbria.

The great Welsh king Hywel Dda (Hywel the Good) was apparently a close ally. In fact, he was so Anglophile that he named one of his sons Edwin, and sponsored a written law code after the English model.

The last Viking king of York, Eric Bloodaxe, was expelled from Northumbria in 954 AD, after Æthelstan’s rule. In that same year, the Scots took Edinburgh from the English.

After 955 AD there was a generation of peace on the island of Britain. As the ‘Anglo Saxon Chronicle’ says of Edgar, King of England (959 – 975 AD) ‘without battle he brought under his sway all that he wished’. He issued laws for ‘all the nations, whether Englishmen, Danes, or Britons’, an interesting recognition of the multi-ethnic character of England at the time.

After Edgar’s death, his successor Edward I reigned briefly. He was murdered in 978 AD at Corfe (Dorset), possibly by the followers of his young half-brother Æthelred, and possibly by his stepmother. Edgar’s half-brother, Æthelred II, who later would acquire the nickname ‘the Unready’, started his long reign (978-1016 AD) at the same time as the emergence of Denmark.

This was the dawning of the ‘second Viking age’, and it was very different from the first. Raids were on a much larger scale, frequently organised by royal leaders, and their object was extortion. In 991 AD, the Danes acquired 4,500 kg of silver in return for going home.

By 1012, payments to the Danes, known as ‘Danegeld’, had increased to 22,000 kg. England was wealthy, and it developed a taxation system that was probably more sophisticated than any other in Europe, which was both a cause and a consequence of the raiding.

The extortion came to an end in 1013, when Harald’s son, Swein Forkbeard, decided to conquer England. He forced Æthelred into exile, although the definitive conquest of England was only achieved under his son Cnut (or Canute). In 1016, Cnut became king of England, and after further campaigns in Scandinavia he could claim in 1027 to be ‘king of the whole of England and Denmark and Norway and of parts of Sweden’.

Cnut was a strong and effective king. He introduced some Danish customs to England, but England also influenced Denmark. For instance, Cnut appointed several Englishmen as bishops in Denmark, and even today, most of the ordinary Danish words of church organisation are English in origin.

In an attempt at reconciliation with the English he had conquered, Cnut married Emma, the widow of Æthelred. She was the daughter of the Duke of Normandy, himself, the descendant of Vikings or Northmen (Normans). She bore Cnut a son, Harthacnut, but she had also had a son by Æthelred, who succeeded Harthacnut as Edward II, the Confessor (1042 – 1066).

When Edward died without children, it was natural that Emma’s great-nephew, Duke William, should lay claim to the throne. It was just as natural that this claim should be resisted by Harold, the son of Godwin, Edward’s most powerful noble.

Harold II successfully beat off the invasion by Harald Hardrada of Norway, defeating him at Stamford Bridge near York in September 1066. Even when he and his troops arrived, exhausted, at Hastings three weeks later to face William’s Norman invaders, he nearly prevailed.

But William won, and the last English royal dynasty perished.

The Norman invasion had begun.