Alfred’s reign and that of his brothers faced a huge threat from Viking raids and then from invasion. In 865 the so-callled Great Heathen Army landed and wintered in East Anglia. This force was led by three sons of the legendary Ragnar Lothbrok, who is the subject of many Norse sagas. These sons were reputed to be Halfdan, Ubba and Ivarr the Boneless, who created what is seen to be the first clearly organised Viking army.

The East Angles, led by King Edmund, brokered for peace in 855. This peace was won at the cost of an agreement which meant tribute would be paid to the Vikings in return for leaving their lands. The Great Heathen Army left East Anglia and headed north, to Northumbria.

In November 866 forces under Ivarr the Boneless took York and looked to improve the defences there, successfully repulsing an attack on the town in spring 867 made by the kings of the small kingdoms of Bernicia and Deira, two rival claimants to the Northumbrian throne, who came together to try to defeat the Danes. In 867 the Northumbrians made peace and a puppet ruler was installed, the Vikings then moved
on to Mercia.

In 867-868 the Vikings made winter quarters in Nottingham. Burgred, King of Mercia, and his councillors asked for help from Æthelred and Alfred. Together the forces of Mercia and Wessex laid siege to the forces in Nottingham, however there was no notable confrontation, with the Mercian’s instead making peace with the Vikings.

In the autumn of 868 the Vikings returned to York. By the end of 869 the Vikings had again moved southwards, this time to Thetford in East Anglia. Edmund, the King of East Anglia, this time fought against the Vikings, instead of looking to make peace and was brutally killed. The story goes that he was captured by Ivarr's forces when praying in a church after his defeat in battle and tied to a tree. He was then shot and killed by Viking archers, whilst praying. He was revered as a saint, known as Edmund the Martyr.

Despite conquering East Anglia the Vikings did not settle in the area, instead they installed a puppet ruler in the region. The army travelled westwards at the end of 870 to a camp east of Reading, where they established themselves in a position well placed for them to raid Wessex from. The Viking army also swelled in size with the arrival of reinforcements in 871.

In early 871 Alfred and King Æthelred fought defensively, fighting several battles, including a victory at Ashdown and defeats at Basing and Marton. The West Saxons faced setbacks with the death Æthelred in April possibly as a result of wounds sustained at a battle at Marton

Depiction of Edmund's martyrdom (12th Century)
(Public domain)