quality:corruption
3rd to 5th centuries

During the Age of Martyrs and at the latest in the fourth century, the majority of the most essential ideas of Marian devotion already appeared in some form – in the writings of the Church Fathers, apocrypha and visual arts. The lack of sources makes it unclear whether the devotion to Mary played a role in liturgical use during the first centuries of Christianity. In the 4th century, Marian devotion in a liturgical context becomes evident.

The earliest known Marian prayer (the Sub tuum praesidium, or Beneath Thy Protection) is from the 3rd century (perhaps 270), and its text was rediscovered in 1917 on a papyrus in Egypt. According to some sources, Theonas of Alexandria consecrated one of the first holy places dedicated to Mary during the late 3rd century. An even earlier place has been found in Nazareth, dated to the previous century by some scholars. Following the Edict of Milan in 313, by the 5th century artistic images of Mary began to appear in public and larger churches were being dedicated to Mary, such as the Basilica di Santa Maria Maggiore in Rome. At the Council of Ephesus in 431, Mary was officially declared the Theotokos, meaning "God-bearer" or "Mother of God". The term had possibly been used for centuries or at least since the early 300s, when it seems to have already been in established use.

The Council of Ephesus was long thought to have been held at a church in Ephesus which had been dedicated to Mary about a hundred years before. Though, recent archeological surveys indicate that St. Mary's Church in Ephesus did not exist at the time of the Council or, at least, the building was not dedicated to Mary before 500. The Church of the Seat of Mary in Judea was built shortly after the introduction of Marian liturgy at the council of Ephesus, in 456, by a widow named Ikelia.

According to the 4th-century heresiologist Epiphanius of Salamis, the Virgin Mary was worshipped as a mother goddess in the Christian sect of Collyridianism, which was found throughout Arabia sometime during the 300s AD. Collyridianism had women performing priestly acts, and made bread offerings to the Virgin Mary. The group was condemned as heretical by the Roman Catholic Church and was preached against by Epiphanius of Salamis, who wrote about the group in his writings titled Panarion.