How did Henri Pirenne describe the role of trade in medieval European cities?

In his influential work Medieval Cities (1925), Henri Pirenne argued that trade was the essential catalyst for the revival of urban life in medieval Europe.12

Pirenne posited that the development of an urban culture was fundamentally dependent on two interconnected factors driven by commerce:

• The Rise of a Bourgeoisie: He identified the emergence of a middle class, or bourgeoisie, that relied on trade for both its wealth and its ability to secure political autonomy from nonurban feudal power holders.2
• Communal Organization: He argued that this merchant class formed communal organizations to achieve the municipal integration necessary to free their cities from the control of local feudal lords or religious authorities.2

Pirenne’s thesis emphasized that the decline of international trade and the disintegration of a money economy following the rise of Arab power in the Mediterranean had previously forced Europe into a closed, subsistence-based agricultural system. Consequently, he viewed the subsequent resurgence of long-distance trade as the primary engine that transformed medieval society, fostered civic independence, and established the "true" urban culture of the Middle Ages.132