| A | B |
| Black Death | Reduced Europe's population by 33%; aka bubonic plague. |
| Great Western Schism | 1378-1415 when the Church had multiple popes; its roots began with Avignon papacy. |
| Renaissance | A rebirth in the arts, education, and all areas of life. |
| Nepotism | The appointing of relatives to important Church positions. |
| Conciliarism | The mistaken idea that Church councils had more power than the pope. |
| Feudalism | A rigid political and social order where serfs worked the land for the lords. |
| Simony | The corruption of religion by money. |
| Lay investiture | Lay people appointing clergy to Church positions. |
| Canon law | The Church laws that developed from abuses within the Church. |
| Crusades | Christian holy wars to recapture the Holy Land from the Moslems. |
| Mendicant | Traveling orders that shared the Faith with a dedication to poverty and simplicity of life |
| Summa Theologica | Summary of Theology. |
| Inquisition | Official Catholic court that examined charges of heresy (1220-1230) |
| St. Thomas Aquinas | He wrote the Summa Theologica and the patron saint of Catholic schools and students. |
| St. Francis of Assisi | Crèche, i.e. Nativity scene started by this saint and founder of the Order of Friars Minor. |
| St. Clare | A good friend of St. Francis of Assisi and was dedicated to a life of poverty. |
| St. Dominic | The rosary was popularized by this saint and founder of the Order of Preachers. |