Final answer:
The political and economic decentralization in Europe from 1200 to 1450 was driven by worsening weather, the bubonic plague, the weakening of the feudal system, rising influence of the merchant class, and the centralization of monarchical power.
Step-by-step explanation:
The causes for political and economic decentralization in Europe from 1200 to 1450 were multifaceted, involving a combination of demographic changes, military shifts, and challenges to monarchical authority. At the outset of this period, worsening weather led to crop failures and food shortages, which were exacerbated by the bubonic plague's rampant spread. This devastation weakened the structured hierarchical society and feudal system and resulted in significant depopulation.
Such events as the Great Famine, the Black Death, and the Hundred Years' War intensified the strains on the feudal system. The loss of agricultural productivity and prevalent diseases caused peasant rebellions against the nobility, further depleting their wealth and diminishing their power. Finally, the centralization of monarchical power and the formation of the modern nation-state began to reduce the influence of the nobility, shifting the traditional power dynamics. This process was also influenced by the clergy's mortality during the Black Death, which made monarchs more dependent on the educated merchant class.