Age of the Fathers and Early Middle Ages

Ecumenical Council

A gathering of the Church's bishops from around the world convened by the Pope or approved by him to address pressing issues in the Church.

Arianism

A heresy developed in the late third century that denied Christ's full divinity, stating that Christ was a created being who was superior to humans but inferior to God.

Antipope

A person claiming to be a pop in opposition to the Pope chosen in accordance with Church law.

Hermit

A person who lives a solitary life in order to commit himself or herself to more fully to prayer and in some cases to be completely free for service to others.

Feudalism

A system that evolved in Western Europe in the eighth and ninth centuries in which society was ordered around relationships derived from the holding of land in exchange for service and protection.

Doctor of the Church

A title officially bestowed by the Church on those saints who are highly esteemed for their theological writings, as well as their personal holiness.

Filioque

Latin for "and from the Son", this phrase was added to the Nicene Creed in the Roman Church to express that the Holy Spirit descended from the Father and the Son, rather than from the Father and through the Son, as the Byzantine Church expressed.

Hypostatic Union

Jesus Christ's divine and human natures in one Divine Person.

Franks

A Germanic tribe who inhabited the Roman provinces of Gaul starting in the sixth century.

Theotokos

A Greek title for Mary meaning "God bearer".

Illuminated Manuscript

A book in which the text is supplemented with artwork such as decorated initials, borders, and illustrations, often using gold and silver. During the Middle Ages, such books were copied and illuminated by hand, work often done by monks.

Papal States

An independent country ruled by the Pope until 1870, covering a wide strip of land in the middle of the Italian Peninsula.

Papal bull

An official letter or charter issued by the Pope, named for the wax seal used to authenticate it.

Simony

Buying or selling something spiritual, such as grace, a Sacrament, or a relic. It violates the honor or God.

Fathers of the Church

During the early centuries of the Church, those teachers whose writings extended the Tradition of the Apostles and who continue to be important for the Church's teachings.

Consubstantial

Having the same nature or essence.

Patriarch (Eastern)

In the Old Testament, this title is given to the male head of a group of tribe. In the Eastern (or Greek) Church, this title refers to a spiritual father. This title is given to the highest ranking bishops in the Church.

Logos

The Greek word meaning "Word"; a title of Jesus Christ found in the Gospel of John that illuminates the relationship between the three Persons of the Holy Trinity.

Vikings

The Scandinavian explorers, merchants, and warriors who invaded and settled in Europe from the late eighth to eleventh centuries.

Iconoclasm

The deliberate destruction of religious symbols.

Abbot

The superior and spiritual leader of a monastery.

Vulgate

The version of the Bible that was translated from Hebrew and Greek into Latin by Saint Jerome and that became the definitive version officially promulgated by the Church.

Christendom

Today this refers to the worldwide community of Christians. In the medieval context, the term refers to the Church's sphere of power and authority, both politically and spiritually.