a term already embraced by Martin Luther; and officially confessed in the Formula of Concord (1577), accepted by Lutheran World Federation. Calvin rejected calling Mary the "mother of God," saying, "I cannot think such language either right, or becoming, or suitable. ... To call the Virgin Mary the mother of God can only serve to confirm the ignorant in their superstitions." 20th century In 1994, Pope John Paul II and Patriarch of the Assyrian Church of the East Mar Dinkha IV signed an ecumenical declaration, mutually recognizing the legitimacy of the titles "Mother of God" and "Mother of Christ." The declaration reiterates the Christological formulations of the Council of Chalcedon as a theological expression of the faith shared by both Churches, at the same time respecting the preference of each Church in using these titles in their liturgical life and piety. Liturgy Theotokos is often used in hymns to Mary in the Eastern Orthodox, Eastern Catholic and Oriental Orthodox churches. The most common is Axion Estin (It is truly meet), which is used in nearly every service. Other examples include Sub tuum praesidium, the Hail Mary in its Eastern form, and All creation rejoices, which replaces Axion Estin at the Divine Liturgy on the Sundays of Great Lent. Bogurodzica is a medieval Polish hymn, possibly composed by Adalbert of Prague (d. 997). The Solemnity of Mary, Mother of God is a Roman Catholic feast day introduced in 1969, based on older traditions associating 1 January with the motherhood of Mary. Iconography One of the two earliest known depictions of the Virgin Mary is found in the Catacomb of Priscilla (3rd century) showing the adoration of the Magi. Recent conservation work at the Catacombs of Priscilla revealed that what had been identified for decades as the earliest image of the Virgin and Child was actually a traditional funerary image of a Roman matron; the pointing figure with her, formerly identified as a prophet, was shown to have had its arm position adjusted and the star he was supposedly pointing to was painted in at a later date. The putative Annunciation scene at Priscilla is also now recognized as yet another Roman matron with accompanying figure and not the Virgin Mary. Recently another third-century image of the Virgin Mary was identified at the eastern Syrian site of Dura Europos in the baptistry room of the earliest known Christian Church. The scene shows