Roughly, the Middle Ages began after the fall of which empire in Western Europe?

The story behind the answer

The collapse of the western half of the Roman Empire in 476 CE, when Romulus Augustulus was deposed by Odoacer, is conventionally used to mark the start of the Middle Ages in Western Europe. With imperial bureaucracy and legions gone, cities shrank, roads and aqueducts decayed, and political power fragmented into Germanic successor kingdoms, reshaping society, economy, and law.

In the East, the Roman state endured as the Byzantine Empire for centuries, so the turning point is a Western one. Later powers—the Carolingian realm in the 8th–9th centuries and the Holy Roman Empire from 962—emerged within this new landscape. Monasteries preserved literacy, the Latin Church knit regions together, and castles and feudal obligations became hallmarks of a world transitioning from classical antiquity to medieval Europe.