Final answer:
Italy led medieval Europe in commercial growth due to the rise of the merchant class, the prosperity of city-states, and its trade connections.
Step-by-step explanation:
Italy led medieval Europe in commercial growth for several reasons. Firstly, the rise of the merchant class in Northern and Central Italy played a significant role in the region's prosperity. These merchants gained their position through financial skill and adapted the feudal aristocratic model to their advantage. Secondly, the city-states of Northern and Central Italy, such as Florence, Venice, and Genoa, became wealthy due to their involvement in trade and their control over specific industries, like woolen textile production. Thirdly, Italy's geographical location and trade connections provided access to trading routes, including those from the Levant and the Baltic, which stimulated economic growth.