When did the Catholic Church first introduce the veneration of Mary?

Question

There does not appear to be any evidence for Marian veneration during the first and second century. As far as I am aware, the Didache (also known as The Teachings of the Apostles) and the Epistle of Barnabas, both of which tend to be considered first-century, do not mention Mary at all.

The phrase "theotokos" (God-bearer or the mother of God) seems to be attributed to Athanasius and Gregory of Nazianzus during the fourth century.

My understanding is that during the fifth century, the Council of Ephesus (A.D. 431) endorsed the title “theotokos.” After this event influential theologians like Augustine of Hippo started focusing even more time and attention on doctrines elevating the position of Mary.

Please note that this question is not about whether the veneration of Mary is right or wrong. I simply need to establish the time line of events within the Church that led to the acceptance of the title "theotokos" at the Council of Ephesus (A.D. 431) and how the veneration of Mary developed thereafter.

EDIT: I found this article on the subject: https://classictheology.org/2021/11/29/the-history-of-mary-veneration-a-protestant-prospective/

Answer 1

OP: the time line of events within the Church that led to the acceptance of the title "theotokos" at the Council of Ephesus (A.D. 431) and how the veneration of Mary developed thereafter.

Veneration (Latin: veneratio; Greek: τιμάω timáō),[a] or veneration of saints, is the act of honoring a saint, a person who has been identified as having a high degree of sanctity or holiness.

A benign form of veneration actually began very early in Christian history.

Justin Martyr Dialogue with Trypho Chapter C

that He became man by the Virgin, in order that the disobedience which proceeded from the serpent might receive its destruction in the same manner in which it derived its origin. For Eve, who was a virgin and undefiled, having conceived the word of the serpent, brought forth disobedience and death. But the Virgin Mary received faith and joy, when the angel Gabriel announced the good tidings to her that the Spirit of the Lord would come upon her, and the power of the Highest would overshadow her: wherefore also the Holy Thing begotten of her is the Son of God;2333 and she replied, ‘Be it unto me according to thy word.’ ”

Irenaeus in Against Heresies Book V Chapter XIX argued this way.

For just as the former [Eve] was led astray by the word of an angel, so that she fled from God when she had transgressed His word; so did the latter [Mary], by an angelic communication, receive the glad tidings that she should sustain (portaret) God, being obedient to His word. And if the former did disobey God, yet the latter was persuaded to be obedient to God, in order that the Virgin Mary might become the patroness4617 (advocata) of the virgin Eve. And thus, as the human race fell into bondage to death by means of a virgin, so is it rescued by a virgin; virginal disobedience having been balanced in the opposite scale by virginal obedience.

Note the early idea that Mary would "sustain" or "bear" or "birth" God.

Tertulian continues the comparison between Eve and Mary On the Flesh of Christ Chapter XVII

For it was while Eve was yet a virgin, that the ensnaring word had crept into her ear which was to build the edifice of death. Into a virgin’s soul, in like manner, must be introduced that Word of God which was to raise the fabric of life; so that what had been reduced to ruin by this sex, might by the selfsame sex be recovered to salvation. As Eve had believed the serpent, so Mary believed the angel.7185 The delinquency which the one occasioned by believing, the other by believing effaced. But (it will be said) Eve did not at the devil’s word conceive in her womb. Well, she at all events conceived; for the devil’s word afterwards became as seed to her that she should conceive as an outcast, and bring forth in sorrow. Indeed she gave birth to a fratricidal devil; whilst Mary, on the contrary, bare one who was one day to secure salvation to Israel, His own brother after the flesh, and the murderer of Himself. God therefore sent down into the virgin’s womb His Word, as the good Brother, who should blot out the memory of the evil brother. Hence it was necessary that Christ should come forth for the salvation of man, in that condition of flesh into which man had entered ever since his condemnation.

So, the veneration in a benign sense began very early. That it may be taken to what some may consider as extremes is fairly well known.

The term "theotokos" arose out of the milieu about the nature of Christ. 100% man 100% God. How did it work? In that link, you'll notice the same idea of God-bearer, hinting back to Irenaeus as he argued against the "phantom body" made of star dust idea of Christ. Same with Tertulian who argued for the normal birth of Christ. God bearer.

As to the Council of Ephesus, the argument was between Nestorius who divided Christ into two and Cyril of Alexandria who maintained Christ was one. This history helps clarify the issue.

As Cyril of Alexandria puts it:

The holy and great Synod therefore says, that the only begotten Son, born according to nature of God the Father, very God of very God, Light of Light, by whom the Father made all things, came down, and was incarnate, and was made man, suffered, and rose again the third day, and ascended into heaven. These words and these decrees we ought to follow, considering what is meant by the Word of God being incarnate and made man. For we do not say that the nature of the Word was changed and became flesh, or that it was 198 converted into a whole man consisting of soul and body; but rather that the Word having personally united to himself flesh animated by a rational soul, did in an ineffable and inconceivable manner become man, and was called the Son of Man, not merely as willing or being pleased to be so called, neither on account of taking to himself a person, but because the two natures being brought together in a true union, there is of both one Christ and one Son; for the difference of the natures is not taken away by the union, but rather the divinity and the humanity make perfect for us the one Lord Jesus Christ by their ineffable and inexpressible union.

From this, the veneration of the Mother of God developed further.

Hope that helps.

EDIT TO ADD:

We've seen the early idea of veneration and examples applied to Mary. As mentioned in the comments, the stepping stones to near worship of Mary had begun. Was it in Scripture? Not really, though some believe so without even needing to do so, given the idea that their Tradition is equivalent to Scripture. I digress.

Let's expand the idea of veneration from "simple honoring" to "dulia", "hyperdulia", and "latria".

(Greek doulia; Latin servitus), a theological term signifying the honour paid to the saints, while latria means worship given to God alone, and hyperdulia the veneration offered to the Blessed Virgin Mary. St. Augustine (City of God X.2) distinguishes two kinds of servitus: "one which is due to men . . . which in Greek is called dulia; the other, latria, which is the service pertaining to the worship of God". IBID

Mentioned earlier is this link to the Veneration of Mary and what it has come to mean. What came after those early stepping stones?

Here's Augustine pronouncing the ever-virgin motif.

not such a nature as is conceived between the two sexes through carnal lust, which is born in sin, and whose guilt is washed away in regeneration; but such as it behoved a virgin to bring forth, when the mother’s faith, not her lust, was the condition of conception. And if her virginity had been marred even in bringing Him forth, He would not have been born of a virgin; and it would be false (which God forbid) that He was born of the Virgin Mary, as is believed and declared by the whole Church, which, in imitation of His mother, daily brings forth members of His body, and yet remains a virgin.

Additional themes were also developed, though perhaps less clearly.

Answer 2

When did the Catholic Church first introduce the veneration of Mary?

For traditional Catholics, the response would in simple terms be that it was passed down from Apostolic Times! Meaning that the veneration of Mary was passed down from the apostles themselves. However, to prove this historically would seem to be hard to support.

So I am going to postulate that the earliest veneration of Mary can be found in the Bible itself!

Can we recall the scene in the Gospel of St. Luke of the Visitation of Mary to her cousin St. Elizabeth? Remember that conversion these two holy women had?

Now Elizabeth cried out in a loud voice that Mary was blessed amongst women! As Catholics and Orthodox for that matter we have preserved this in our veneration towards Mary...

39 And Mary rising up in those days, went into the hill country with haste into a city of Juda.

40 And she entered into the house of Zachary, and saluted Elizabeth.

41 And it came to pass, that when Elizabeth heard the salutation of Mary, the infant leaped in her womb. And Elizabeth was filled with the Holy Ghost:

42 And she cried out with a loud voice, and said: Blessed art thou among women, and blessed is the fruit of thy womb.

43 And whence is this to me, that the mother of my Lord should come to me?

44 For behold as soon as the voice of thy salutation sounded in my ears, the infant in my womb leaped for joy. - Luke 1:39-44

What further cements the idea that the inspiration to venerate Mary in a special way can be found in the Magnificat.

Both East and West, have cherished the tradition of chanting the Magnificat as a way of preserving the subtle prophecy that Mary would be considered ”blessed” for all generations!!!

It must also be remembered that the Gospels were more concerned about Jesus and his mission to save humanity from sin. Nevertheless Mary had a role to play in all this... As the Early Church was one that was existing in a time of persecution, Mary had to be kept as safe as possible. It not mysterious that St. John took the Virgin Mary to Ephesus to live out the rest of her life in secrecy. Mary was regarded as the most intimate person who knew Jesus and too much "talk" or "written documentation" could have gotten Mary martyred. All the apostles were martyred... St. John took Mary into his own house and kept Jesus' mother safe. If the Apostles took this much care to safeguard Mary is an indication that Mary was indeed venerated in a special way.

Mary's Song of Praise: The Magnificat

46 And Mary said: My soul doth magnify the Lord.

47 And my spirit hath rejoiced in God my Saviour.

48 Because he hath regarded the humility of his handmaid; for behold from henceforth all generations shall call me blessed.

49 Because he that is mighty, hath done great things to me; and holy is his name.

50 And his mercy is from generation unto generations, to them that fear him.

51 He hath shewed might in his arm: he hath scattered the proud in the conceit of their heart.

52 He hath put down the mighty from their seat, and hath exalted the humble.

53 He hath filled the hungry with good things; and the rich he hath sent empty away.

54 He hath received Israel his servant, being mindful of his mercy:

55 As he spoke to our fathers, to Abraham and to his seed for ever. - Luke 1:46-55

Outside the Sacred Scriptures, the Sub Tuum Praesidium remains the oldest known hymn (3rd or 4th century) in honour of Mary and is well attested among the believers of the Catholic Church, the Eastern Orthodox Church and Oriental Orthodoxy.

From the Early Church:

For the attitude of the Churches of Asia Minor and of Lyons we may appeal to the words of St. Irenaeus, a pupil of St. John's disciple Polycarp [145]; he calls Mary our most eminent advocate. St. Ignatius of Antioch, part of whose life reached back into apostolic times, wrote to the Ephesians (c. 18-19) in such a way as to connect the mysteries of Our Lord's life more closely with those of the Virgin Mary. For instance, the virginity of Mary, and her childbirth, are enumerated with Christ's death, as forming three mysteries unknown to the devil. The sub-apostolic author of the Epistle to Diognetus, writing to a pagan inquirer concerning the Christian mysteries, describes Mary as the great antithesis of Eve, and this idea of Our Lady occurs repeatedly in other writers even before the Council of Ephesus. We have repeatedly appealed to the words of St. Justin and Tertullian, both of whom wrote before the end of the second century. - The Blessed Virgin Mary

St. Epiphanius of Salamis in the 4th century was the first author in mentioning the traditional faith of the Assumption of Mary in body and soul to the Heaven, and coming from Ephesus.

An Egyptian Coptic ostracon that dates to around the year 600 bears the Greek words: "Hail Mary full of grace, the Lord is with thee; blessed art thou amongst women and blessed is the fruit of thy womb, because thou didst conceive Christ, the Son of God, the Redeemer of our souls". This Eastern variant of the Ave Maria was apparently intended for liturgical use, just as the earliest form of the Hail Mary in the Western Church took the shape of an antiphon. However, there is little or no trace of the Hail Mary as an accepted "devotional formula" before about 1050. While two Anglo-Saxon manuscripts at the British Museum, one of which may be as old as the year 1030, show the words "Ave Maria" and "benedicta tu in mulieribus et benedictus fructus ventris tui", it is not certain when these clauses were first joined to make one prayer. - History of the Rosary