Grain was the literal lifeblood of the medieval city. To prevent famine and civil unrest, city councils often intervened in the market:
Much like modern trade blocs, medieval cities relied on regional networks to overcome obstacles like non-tariff barriers and physical constraints on transportation.
Every transaction was heavily monitored. In some regions, duplicate subscriptions or unauthorized trades were strictly penalized to ensure the city's food supply remained stable and its tax revenue secure. Conclusion