| Heavy Plow | part of the agricultural revolution; improved planting efficiency |
| Collar Harness | part of the agricultural revolution; improved planting efficiency |
| Three Field System | part of the agricultural revolution; farming technique that left one field out of three sallow for a year to replenish the soil |
| Bourgeoisie | townspeople not attached to land |
| Guilds | groups of artisans sharing similar hours, wages, products and prices |
| Common Law | law system developed by judges sharing case files with each other |
| The Doomsday Book | book of taxes |
| Muhammad | born in Mecca, founder of Islam |
| Mecca | birthplace of Muhammad, holiest site in Islam |
| Medina | town to which Muhammad and his followers fled to escape persecution |
| Hijra | the flight to Medina |
| The Quran | the transcription of Muhammad's revelations from the angel Gabriel |
| Ali | Muhammad's nephew and one of Islam's leaders after his death |
| Seljuk Turks | invaded Asia Minor preceeding the First Crusade |
| Urban II | requested the First Crusade, against the Seljuk Turks |
| Clermont | site at which Urban II requested the First Crusade |
| Peter the Hermit | persecuted Jews during the Peoples' Crusade |
| Simony | the purchasing of church offices |
| Investiture | the practice of giving authority symbols to church officials |
| Excommunication | being cut off from the church |
| Gregory VII | strong advocate of increased papal power |
| Henry IV | challenged Pope Gregory VII |
| University of Paris | specialized in theology, salaries paid by the church |
| University of Bologna | specialized in law, salaries paid by students |
| Courtly Love | relationship between a knight and his mistress, an essential element in the Romance stories |
| Chivalry | code of conduct and honor for a knight |
| Tournaments | started out as brutal and dangerous, later became more refined and like a game |
| Romances | love stories about knights |
| Romanesque Architecture | characterized by huge, thick stone walls with small windows |
| Gothic Architecture | characterized by pointed arches, high ceilings, flying buttresses, and large stained-glass windows |
| Bubonic Plague | symptoms began with black pustules on the skin, followed by internal hemorrhaging, then usually death |
| Rat Flea | the carrier of the Bubonic Plage, and a hardy survivor that can live in almost any conditions |
| Flagellant Movement | the practice of beating oneself with whips to drive out evil |
| Edward III | laid claim to the French throne, began the Hundred Years' War |
| Joan of Arc | peasant French girl, saw visions and led the French army to victories |
| The Long Bow | crucial element in England's victory over France in the Hundred Years' War |
| Jacquerie | peasant revolt in France |
| Philip IV | taxed clergy to pay for a war; after much conflict with the Pope, he called the Estates General to request support |
| Boniface VIII | Pope that struggled against Philip IV |
| Babylonian Captivity | when Clement V remained in France and established the seat of the papacy in Avignon |
| The Conciliar Movement | refers to the election of two separate popes by the Council of Pisa and the Council of Constantine |
| The Great Schism | developed after the Conciliar Movement, refers to the time when there were two separate churches and popes |
| John Wycliffe | disagreed with much church doctrine; advocated the translation of the Bible |
| Dante | Italian satirist, wrote "The Divine Comedy," |
| The Divine Comedy | satirical poem composed by Dante, an allegorical description of hell |