In AD71, the Roman Governor of Britain, Quintus Petilius Cerealis, led his troops northwards from Lincoln to invade 'Brigantia'. Recognising a good military strongpoint, he based his camp at the juncture of two rivers, the Ouse and the Foss.

Having conquered the Brigantes, the Ninth Legion built a fortress on the site of their camp and called it Eboracum. On the departure of the Ninth Legion in AD120, the Sixth Legion took command of the fortress which eventually enclosed 50 acres and housed a garrison of several thousand soldiers.

New roads were constructed, a civilian town grew up outside the fortress walls and Eboracum became the capital of Lower Britain and a leading city of the Roman Empire.

Several Emperors visited Eboracum and Severus held his Imperial Court there until he died in AD211.

In AD306, Emperor Constantius Chlorus died in Eboracum and was succeeded by Constantine, his son. Constantine the Great as he became known was proclaimed Emperor and the proclamation is thought to have been held on the site of the present Minster. Constantine went on to found Constantinople and was the first Christian Emperor of Rome.

The Legions, who occupied Eboracum until around AD410, had their headquarters where the Minster stands today and, during restoration work, Roman remains were discovered beneath it. These included a 31 foot Roman pillar which was re-erected and can now be seen near the Minster's South Entrance.