Noricum falls

There exists a famous anecdote from saint Severinus' vita. Severinus lived in old Noricum, older Helvetia. Here a Roman camp was supplied until the middle 400s. The camp sent envoys across the Alps to Rome... wherever that was, probably Ravenna. They never got paid; often the envoys would get ripped by bandits. Here's the sequel: Historic Genomes Uncover Demographic Shifts and Kinship Structures in Post-Roman Central Europe.

Under the Empire, Romans afield would be... Romans. Some married locally or at least retired to a local colonia like, um, Cologne or LinColn. But most just wanted home to their native town in southern Gaul or wherever. And I guess some slipped into monasteries, like Severinus. But the monkish life ain't for everyone.

This genetic study notes where soldiers quit hoping to go back. It seems the locals weren't really offering a lot of likely maidens. The men, here, took wives from further north; deutscher wives. Everyone likes tall muscular blondes Nah - they just worried about inbreeding. They didn't even do levirate marriages, in accord with the Catholic ban. Severinus taught them well.