Final answer:
Trade during the Middle Ages expanded due to improved trade routes, the development of commercial infrastructure, the rise of a wealthy merchant class, and the Crusades' influence. The influx of precious metals from the New World and the innovation of financial practices in cities like Florence also played significant roles.
Step-by-step explanation:
The expansion of trade during the Middle Ages can be attributed to several factors, including the revival of trade routes, the emergence of maritime networks, the development of financial infrastructure such as double-entry bookkeeping, and the growth of the merchant class. Following the plague, the demand for better wages by peasants and artisans led to increased commercial activity. Additionally, the establishment of caravansaries facilitated secure trade and the exchange of ideas. The desire for luxury goods in Europe inspired further exploration and the establishment of direct trading contacts. The Italian city-states played a pivotal role in revitalizing trade across Europe, and Venice, in particular, gained enormous wealth through trade with Islamic merchants. Moreover, the advent of the Crusades contributed to increased demand for Eastern luxury goods and motivated European powers to seek new trade routes.
Financial and economic growth were also catalyzed by the infusion of precious metals from the New World, with Spain extracting large sums of gold and silver from Mesoamerica. The rise of powerful merchant cities like Antwerp and Amsterdam in the Netherlands marked a shift in Europe's economic centers away from the Mediterranean.