15 A.C. the Romans, who had envisaged the Celtic kingdom for a longer time, took over the rule. They started to build their town at the point where the old town of Salzburg still remains today. Since the rule of the Emperor Claudius the city was called “Municipium Cladium Iuvavum” and became one of the most important cities in the Roman province of Noricum.
Archaeological excavations proved the existence of an upper bourgeoisie and an extended trade district. One finding is an amphora with many different sea fish and crustaceans.
Times were not always safe: Germanic peoples were a constant threat to the Iuvavum. 170 A.D. the Marcomanians devastated the thriving Iuvavum. Parts of the city could be reconstructed, but its growth had been enormously slowed.
On the recommendation of King Odoaker the Romans retreated to Italy in 448. Very few people, mostly of Germanic and Celtic origin, were left behind. Today there is no written data about the time of the migration of the peoples. Still it is a fact that, in the 6th century, the Bajuvarian started settling down around Flachgau and Tennengau as well as in the area of today’s urban area. Besides Theodbert, the son of the Duke of Bavaria, used to reside in the area of today’s Nonnberg.