The High Middle Ages refers to the 12th and 13th centuries in Europe. During this time:
1. Agricultural innovations like the heavy plow, crop rotation, irrigation, and watermills/windmills increased food production and reduced famines. This led to population growth and an economic boom.
2. New cities grew along trade routes, as peasants fled serfdom and merchants sought protection. The largest cities had over 50,000 inhabitants. Urban societies developed social hierarchies and ethnic neighborhoods like Jewish quarters.
3. International trade expanded through routes like the Mediterranean and increased the growth of banking practices such as bills of exchange, credit, and trade fairs. This economic growth supported the rising middle class