Feudalism: A political and economic system of Europe from the 9th to about the 15th century based on holding all land in fief or fee and the resulting relation of lord to vassal and characterized by homage, legal and military service of tenants, and forfeiture.
Feudalism was the leading way of political and economic life in the Medieval era. Monarchs, like kings and queens, maintained control and power by the support of other powerful people called lords.
Lords were always men who owned extravagant homes, called manors, and estates in the country. These men would pledge their support – including providing troops, money, food and more – to the king. They often supplied and funded the king's wars.
Lords could have a variety of other official titles including earl, marquis, baron or viscount.
Lords provided some of their land to vassals, or tenants, in exchange for their support to the Lord. Vassals generally were required to serve guard duty, and, later, they paid a fee to acquire mercenaries (soldiers-for-hire).
Vassals were in a somewhat higher class than peasants. In exchange for protection, land to work and a place to live, peasants provided the Lord with labor or a share of the produce or livestock yielded from his lands.
The feudal system broke down in the 13th and 14th centuries following massive abuses.