The Roman conquest of Britain had begun in CE 43, but advance beyond the Humber does not take place until the early 70s CE.

This is because the people in the area known as the Brigantes by the Romans, who had became a Roman client state, had become more hostile to Rome when their leadership changed.

Cerialis leads the Ninth Legion north from Lincoln across the Humber.

The fortress of Eboracum is founded in 71 CE when Cerialis and the Ninth Legion construct a military fortress (castra) on flat ground above the River Ouse near its junction with the River Foss.

In the same year Cerialis is appointed Governor of Britain.

The Roman fort of Eboracum, from its foundation, covers an area of fifty acres (two hundred thousand square meters) the standard size for a legionary fortress.

The layout of the fortress also follows the standard for a legionary fortress with wooden buildings inside a square defensive boundary.

These defenses originally consist of turf ramparts on a green wood foundation, built between 71 and 74 CE by the Ninth Legion.

A legion at full strength at this time numbers some fifty-five hundred men, and provides new trading opportunities for enterprising local people, who doubtless flock to Eboracum to take advantage of them.

As a result, permanent civilian settlement will soon grow up around the fortress, especially on its southeast side.

Civilians also settle on the opposite side of the Ouse, initially along the main road from Eboracum to the southwest.

Located about one hundred and ninety miles (three hundred kilometers) north of Londinium, Eboracum will become the city of York.

His illness fatal, Severus withdraws to Eboracum.

He is famously said to have given the advice to his sons: "Be harmonious, enrich the soldiers, and scorn all other men" before he died on February 4, 211.

Caracalla attempts to take over command but when his troops refuse to recognize him as emperor, he makes peace with the Caledonians and retreats south of Hadrian's Wall to press his claim for the throne.

The Romans will never campaign deep into Caledonia again: they will soon withdraw south permanently to Hadrian's Wall.

Edmund is successful in reconquering Northumbria in 944.

His ally Amlaíb of York loses his throne in the same year and leaves for Dublin in Ireland.

The course of events in Northumbria while Amlaíb is in Ireland is uncertain.

While Edmund certainly controlled Northumbria after Amlaíb was expelled and Ragnall killed, he may soon after have lost control of the north to a Scandinavian king named Eiríkr, usually identified with Eric Bloodaxe.

If Erik did rule in Northumbria before Edmund's death, it was only for a short time.

After Edmund is killed in 946, he is succeeded by his brother Eadred.

The Anglo-Saxon Chronicle records that Eadred "reduced all the land of Northumbria to his control; and the Scots granted him oaths that they would do all that he wanted". (Swanton, Anglo-Saxon Chronicle, pp. 112–113, Mss A & D, s.a. 946, Ms. E, s.a. 948.)