banquet: an elaborate meal or feast given by kings and nobles in the great hall of a castle.
bishop: a religious leader of noble rank, above a priest, administers from a cathedral.
catapult: a giant war machine that could hurl a heavy rock against the wall of a castle or town.
coat of arms: the family emblem that is worn on a knight's tunic and shield that identifies what family he belongs to.
chivalry: the qualities and conduct that ideal knights should have. These included being courteous to women, keeping their word, being respectful of the Church, having pity for the poor and being brave in battle.
Dark Ages: the first part of the Middle Ages. The period of time between the fall of the Roman Empire to the end of 10th century characterized by war and disorder.
feudal system: a social system where kings gave noblemen grants of land in exchange for noblemen's pledges to provide soldiers for the king. Nobles could then divide their land among knights and lower lords who would fight for their nobleman in times of war. The peasant farmers were at the bottom of the feudal system and worked the land for the lord of the manner. 
heresy: A belief that is different from what is commonly accepted as Christian teachings of the Church. A person who was accused of heresy was called a heretic and could be punished with a fine, a long jail term, banishment or even torture and death.
illuminated
manuscripts: hand-printed books and documents that had hand-painted decorations.
joust: a battle or mock battle between two knights who would charge each other and attempt to knock each other off their horses by hitting with a lance or long pole.
knight: a soldier who fought on horseback for a king or lord.
lord: a powerful and wealthy ruler of land who rented land to peasants.
manor: an area of land that was owned by a lord.
medieval: the time roughly from the fifth century to the end of the 15th century (A.D. 400 to A.D. 1400); also known as the Middle Ages. The period of time between classical ancient Greece and Rome and the Renaissance.
monk: a religious man who lives a secluded life and takes vows of poverty, chastity and obedience.
page: a boy from 7 to 13 years old who is in training to become a squire and then possibly a knight.
parchment: thin animal skin used as paper.
peasant/serf: a person at the lowest level of society who worked the land for nobles.
squire: a boy over 14 years of age who assisted a knight.
tapestry: a woven wall hanging that decorated castle walls and helped keep drafts out.
tournament: a competition between knights.
trencher: a slab of stale bread used as a plate. 
troubadours: traveling entertainers who recited poems, sang songs, and told stories.