| Term | Definition |
| Justinian | Byzantine Emperor in the 6th. century |
| Justinian Code | Legal code that was the foundation for Byzantine law for almost 900 years. |
| Plague of Justinian | Outbreak of Bubonic Plague in Byzantium in 6th century |
| Hagia Sofia | Church built in 6th century in the city of Constantinople |
| Scholastica | Nun and sister of St. Benedict |
| German Christianized | Process in which polytheist Germanic peoples converted to Christianity |
| Charles the Hammer | Charles Martel; a french mayor who was a hero to Christians in Europe. |
| Charlemagne | Frankish King who expands empire and take the title of Emperor. |
| Invasions of Europe | Magyars, Muslims, and Vikings invaded Europe during the Middle Ages. |
| Treaty of Verdun | Document which split Charlemagne's Empire into three pieces. |
| Christianity Splits | Disputes over doctrine lead to two churches: Catholic in the west and Orthodox in the East. |
| Malik Shah | considered the greatest Seljuk (or Turkish) sultan |
| Pope Urban II | Christian leader who called upon Europe to retake Holy Lands. |
| Notre Dame | Gothic Cathedral built in Paris during the 12th & 13th centuries |
| The Crusades | A series of military campaigns to retake the Holy Lands from Muslim control. |
| Holy Roman Empire | the strongest political state in Europe from 936 to 1100. |
| Eleanor of Aquitaine | Married both a french and English king. Mother of Richard I. |
| Richard I | English King known as the 'Lion-Hearted' for his bravery during the Third Crusade. |
| Saladin | Muslim leader who retook Jerusalem from European forces. |
| Henry II | Father of Richard II and a king of England. |
| Genghis Khan | Mongolian general who conquered massive territories in Asia. |
| Magna Carta | 'Great Charter' set legal limits to the King of England's power. |
| Thomas Aquinas | Christian scholar who lived in the 13th century. |
| The Black Death | Outbreak of Bubonic Plague in Europe |
| Hundred Years War | Conflict between England and France during the 14th & 15th century |
| Joan of Arc | Teenage girl who helped defeat English forces. |
| Reconquista | When Spanish forces drove Muslims from Spain |
| Ivan III | First Czar of Russia; he wanted to create a new Roman Empire |