"Know ye, brethren," [the saint] said, "that as the children of Israel were delivered out of the land of Egypt, so all the peoples of this land are destined to be freed from the unrighteous sway of the barbarians. For all shall depart from these towns with their possessions, and shall reach the Roman province without any loss by capture....This shall profit, not me, but you. For these places, now thronged with inhabitants, shall be rendered a solitude so utterly waste that the enemy, thinking to find gold, shall dig up even the graves of the dead." (Eugippius, Life of St. Severinus, 40)

The redoubtable Saint Severinus, as usual, was correct: within a few years of his death, the people of Noricum Ripense (now eastern Austria and Slovenia) would be forced to leave their homes by the Danube and resettled in southern Italy. No source tells us exactly why - but a quick survey of the political situation suggests several potential reasons (hopefully, our late antique gurus /u/FlavivsAetivs and /u/bitparity will be able to correct me if I miss anything!)

Noricum and Raetia had been Roman since the reign of Augustus. From first to last, they were frontier provinces, with substantial troop concentrations along the Danube. Noricum, the focus of our narrative, had additional resources - must notably, rich iron mines. Neither province, however, was very urbanized or populous. The few cities tended to be concentrated along the frontier, where the soldiers and their demands for provisions stimulated the local economy. The population had been largely Celtic in culture before the Roman conquest, but seems to have been solidly Latin-speaking by late antiquity.

Over the course of the mid-fifth century, things fell apart along the upper Danube. The rapid rise and sudden fall of Attila destabilized the whole frontier, the western Roman government in Ravenna had an increasingly difficult time paying the province's remaining soldiers, and barbarian groups to the north and east raided and plundered with virtual impunity. By the 470s, as the western imperial government shuffled toward terminal decline, Roman authority had effectively vanished, leaving only a few frightened and unpaid troops. A frequently-quoted passage from the Life of St. Severinus describes the fate of Noricum's last Roman soldiers:

"So long as the Roman dominion lasted, soldiers were maintained in many towns at the public expense to guard the boundary wall. When this custom ceased, the squadrons of soldiers and the boundary wall were blotted out together. The troop at Batavis, however, held out. Some soldiers of this troop had gone to Italy to fetch the final pay to their comrades, and no one knew that the barbarians had slain them on the way. One day, as Saint Severinus was reading in his cell, he suddenly closed the book and began to sigh greatly and to weep. He ordered the bystanders to run out with haste to the river, which he declared was in that hour be-sprinkled with human blood; and straightway word was brought that the bodies of the soldiers mentioned above had been brought to land by the current of the river." (20)

After this, Noricum was at the mercy of its barbarian neighbors. For decades before the final collapse of Roman authority, the most important local tribe had been the Rugians, settled along the north bank of the Danube. Saint Severinus, who had become the effective leader of the province's Roman population, had cordial dealings with the Rugian king Flaccitheus and his son Feletheus (though he was notably less enthusiastic about the Rugian queen Giso, a fervent Arian "heretic"). Partly through Severinus' good offices, the Rugians established what amounted to a protectorate over the Roman towns along the Danube. In return, however, they conscripted Romans for agricultural work, and took much of their grain as a tax.

But Noricum was never fully integrated into the Rugian realm. It belonged to another barbarian king. In 476, when the barbarian general Odoacer deposed the last western emperor, his rule was effectively limited to Italy. His domains, however, technically included those bits of Raetia and Noricum that had preserved some vestige of Roman governance to the end; and as Odoacer's rule became better established, he sought to firmly establish his authority over these frontier districts. His interest in the area increased dramatically when the eastern emperor Zeno (who suspected Odoacer of conniving at a rebellion against his rule), encouraged the Rugians to invade Odoacer's kingdom. Over the course of two years (487-8), Odoacer completely defeated the Rugians. It was in the wake of this victory that he ordered the remaining Romans of Noricum to be deported to Italy.

Why did Odoacer move the Noricans to Italy? The Life of St. Severinus (our sole source) says only:

"Onoulfus, however, at his brother's [i.e. Odoacer's] command ordered all the Romans to migrate to Italy. Then all the inhabitants, led forth from the daily depredations of the barbarians as from the house of Egyptian bondage, recognized the oracles of Saint Severinus." (44)

Odoacer probably had several motives for ordering the move. He was well aware that Noricum would always be on the extreme edge of his domains, and would be vulnerable to the raids and machinations of his enemies. On the most basic level, he wanted to preserve a substantial group of productive Roman farmers and tradesmen, and to incorporate them firmly into his kingdom and tax base. Since some of Noricum's former Roman soldiers seem to have taken up service with the Rugians, he may have distrusted the loyalty of the population, and wished to deprive his enemies of their services. And he likely wanted to frustrate the designs of the eastern emperor Zeno (to whom he defiantly sent trophies of his victory over the Rugians) by removing potential collaborators from a disputed border zone. As Symmachus would say a few decades later, "The Provinces of Raetia are the bars and bolts of Italy" (Var. 7.4). It would unwise to leave people in the area who might spring the gate.

[According to the last section of this essay, there is evidence for continued Roman occupation of many cities in Noricum, and for local knowledge of Latin into the eighth century. So perhaps Odoacer took only the Norican elite - the people most likely to aid his enemies - back to Italy.]

Whatever Odoacer's motives were, the evacuation seems to have been fairly well organized. It was led was a high-ranking official from Odoacer's court, and presumably supervised by Odoacer's troops. The refugees were given lands in various parts of Italy. Most of them seem to have arrived safely in their new homes - St. Severinus' bones certainly did - but we know nothing about how or where they were settled.