An iconodule is someone who espouses iconodulism, i.e. who supports or is in favor of religious images or icons and their veneration

Veneration

Veneration , or veneration of saints, is a special act of honoring a saint: an angel, or a dead person who has been identified by a church committee as singular in the traditions of the religion. It is practiced by the Eastern Orthodox Church, the Roman Catholic, and Eastern Catholic Churches...

, and is in opposition to an iconoclast

Iconoclasm

Iconoclasm is the deliberate destruction of religious icons and other symbols or monuments, usually with religious or political motives. It is a frequent component of major political or religious changes...

, someone against the use of religious images. The term is usually used in relation to the iconoclastic controversy in the Byzantine Empire

Byzantine Empire

The Byzantine Empire was the Eastern Roman Empire during the periods of Late Antiquity and the Middle Ages, centred on the capital of Constantinople. Known simply as the Roman Empire or Romania to its inhabitants and neighbours, the Empire was the direct continuation of the Ancient Roman State...

; the most famous iconodules of that time being the Saints Theodore the Studite

Theodore the Studite

Theodore the Studite was a Byzantine Greek monk and abbot of the Stoudios monastery in Constantinople. He played a major role in the revivals both of Byzantine monasticism and of classical literary genres in Byzantium...

 and John of Damascus

John of Damascus

Saint John of Damascus was a Syrian monk and priest...

.

The controversy was instigated by Byzantine Emperor Leo III

Leo III the Isaurian

Leo III the Isaurian or the Syrian , was Byzantine emperor from 717 until his death in 741...

 in 726, when he ordered the destruction of icons throughout the empire. St. John of Damascus

John of Damascus

Saint John of Damascus was a Syrian monk and priest...

 argued successfully that to prohibit the use of icons was tantamount to denying the incarnation

Incarnation (Christianity)

The Incarnation in traditional Christianity is the belief that Jesus Christ the second person of the Trinity, also known as God the Son or the Logos , "became flesh" by being conceived in the womb of a woman, the Virgin Mary, also known as the Theotokos .The Incarnation is a fundamental theological...

, the presence of the Word of God in the material world. Icons reminded the church of the physicality of God as manifested in Jesus Christ.

Veneration of icons was restored by the Second Council of Nicaea

Second Council of Nicaea

The Second Council of Nicaea is regarded as the Seventh Ecumenical Council by Roman Catholics, Eastern Orthodox, Eastern Catholic Churches and various other Western Christian groups...

 (Seventh Ecumenical Council

Ecumenical council

An ecumenical council is a conference of ecclesiastical dignitaries and theological experts convened to discuss and settle matters of Church doctrine and practice....

) in 787. However this was met with opposition, in particular of Charlemagne

Charlemagne

Charlemagne was King of the Franks from 768 and Emperor of the Romans from 800 to his death in 814. He expanded the Frankish kingdom into an empire that incorporated much of Western and Central Europe. During his reign, he conquered Italy and was crowned by Pope Leo III on 25 December 800...

. The last outburst of iconoclasm in the Byzantine Empire was overcome in 843, in an event celebrated as the Feast of Orthodoxy

Feast of Orthodoxy

The Feast of Orthodoxy is celebrated on the first Sunday of Great Lent in the liturgical calendar of the Eastern Orthodox Church and Greek-Catholics...

.