Muslim conquests severed Europe from the commercial vitality it later needed
Evidence
The Carolingian Empire did little to repair the “rot” that anticipated the restructuring of Europe in feudal terms. The Muslim conquests of the Mediterranean in the seventh and eighth centuries had deprived the European economies of the urban, commercial, productive, and cultural vitality they required for their reconstruction. — Cedric J. Robinson, Black Marxism_ The Making of the Black…, 134