Medieval economies were primarily based on agriculture, with most people living in rural areas and working the land. The feudal system structured society, where lords owned large estates and peasants, or serfs, worked the land in exchange for protection and a place to live. This system created a self-sufficient economy, with local markets for trading goods like grain, livestock, and textiles. Trade began to flourish in the later Middle Ages, especially in cities like Venice and Florence. Guilds formed to regulate trades and protect the interests of craftsmen. The rise of towns and trade routes helped stimulate economic growth, leading to the development of a more complex economy that included banking and currency.