Aquileia (in Friuli-Venezia Giu­lia), one of the largest and wealth­i­est cities of the Ear­ly Roman Empire, was destroyed by Atti­la in the mid-5th cen­tu­ry. Most of it still lies unex­ca­vat­ed beneath the fields, and as such it con­sti­tutes the great­est archae­o­log­i­cal reserve of its kind. The patri­ar­chal basil­i­ca, an out­stand­ing build­ing with an excep­tion­al mosa­ic pave­ment, played a key role in the evan­ge­liza­tion of a large region of cen­tral Europe.