Alfred believed the Vikings had been allowed to ravage his kingdom because his people had given up their commitment to truth and learning. Having set about rebuilding education in Wessex, and having learned to read and write Latin himself, Alfred moved on to the second stage of his plan to protect the kingdom against further Viking incursions.

The Viking’s key strategic advantages were mobility and surprise. When faced with an organised defensive force, a Viking raiding party preferred discretion over valour. Despite their reputation for berserk fury, most Vikings were in it for the money. Given the choice, they would seek refuge behind fortifications or take to their boats than risk everything in a full-scale battle. But the time taken to assemble the fyrd, the free men of a district, meant that any half competent Viking commander could raid and depart before anything could be done to stop him. Even the Great Army that Alfred had defeated, which was set upon conquest rather than raiding, used the same tactics, picking the time and place to strike, often waiting for when its enemies were occupied with harvest or festivals.

Alfred dug deep into the problem he faced, working down to first principles. He saw that, to counter the mobility of a Viking army, he required forces that could be assembled quickly and moved fast: he needed a mounted, standing army. This was a radical change from Anglo-Saxon practice. What’s more, it would be far more costly to the magnates required to provide the mounted troops. But by 893, when the Anglo-Saxon Chronicle describes in passing the results of the changes the king had inaugurated, Alfred had persuaded, cajoled, suborned and wheedled his nobility into line. Half the kingdom’s warriors were kept on duty, with the other half held in reserve.

We know this force was mounted because, in its description of the actions and campaigns of the 890s, the Chronicle repeatedly refers to Alfred’s forces riding after the Viking army. The horses were not the great war beasts of the high medieval period but smaller animals, not that much larger than ponies, but ideal for transporting the relatively lightly armoured warrior of the time.

By retaining half the warriors in reserve, that is, still living in their landholdings, Alfred also ensured the maintenance of the king’s peace. For these warriors fulfilled the function of a police force as well as an army, deterring bands of brigands from raiding the small farming communities and religious establishments that dotted the land. Having men in place on the ground also meant that those on service were less likely to go running back to their homes to look after hearth and family. But this mobile strike force was only half the solution. Alfred still needed to find a way to protect the ordinary folk of his kingdom, the ones whom the Vikings would seize and sell at the slave markets of Dublin.