In economic history, DeLong and Shleifer show that in second-millennium Europe, city growth correlated with non-absolutist government. Unlike the urban elites of antiquity, medieval elites were rural, making urban population a proxy for commerce rather than imperial extraction. London grew as a river crossing and commercial center before Norman royal institutions centralized around Westminster, while Hanseatic cities formed entirely along maritime trade networks, obtaining imperial immediacy as functional city-states dependent on imported grain from lands they did not rule. pedestrianobservations.com