Roman institutional forms survived the barbarian conquests largely intact

Evidence

Pirenne observes: “These things were retained: the language, the currency, writing (papyrus) weights and measures, the kinds of foodstuffs in common use, the social classes, the religion—the role of Arianism has been exaggerated—art, the law, the administration, the taxes, the economic organization.” — Cedric J. Robinson, Black Marxism_ The Making of the Black…, 1471