My Question: Which Church Fathers thought of Mary as a Queen?
The Church Fathers can be both early and late(max 500AD).
Many Church Fathers have written about the Queenship of Mary either directly or indirectly.
To start with, let us answer the question as to who are the Church Fathers according Catholicism?
The Fathers of the Church are so called because of their leadership in the early Church, especially in defending, expounding, and developing Catholic doctrines. For the first two centuries, most of these men were bishops, although in later years certain priests and deacons were also recognized as Fathers.
The list includes such notables as: Clement of Rome (d. A.D. 97), Ignatius (d. 110), Polycarp (d. 155), Justin Martyr (the Church’s first major lay apologist; d. 165), Irenaeus (d. 202), Cyprian (d. 258), Athanasius (d. 373), Basil (d. 379), Cyril of Jerusalem (d. 386), Ambrose (d. 397), John Chrysostom (d. 407), Jerome (d. 420), Augustine (d. 430), Cyril of Alexandria (d. 444), Pope Leo the Great (d. 461), and Pope Gregory the Great (d. 604).
The Church demands four major characteristics to be exhibited in the life and works of an early Church leader if he is to be considered a Father of the Church. These are antiquity, meaning that he lived before the eighth century (the death of St. John Damascene [cir. A.D. 750] is generally regarded as the close of the age of the Fathers); doctrinal orthodoxy; personal sanctity; and approval by the Church. - Who were the Church Fathers?
Which Church Fathers thought of Mary as a Queen (prior to the year 500 AD)?
The Fathers of the Church unanimously called the Blessed Virgin Mary their Queen. Here is a sample of a few of the Fathers in their own words:
St. Jerome tells us "We should realize that Mary means Lady in the Syrian language."
St. Peter Chrysologus says "The Hebrew name ‘Mary’ means ‘Domina’ [Lady] in Latin. The Angel therefore calls her Lady so that the Mother of the Lord, whom the authority of her Son made and caused to be born and to be called the Lady, might be without servile fear."
St. Ephrem has Mary saying: "Let Heaven sustain me in its embrace, because I am honored above it. For heaven was not Thy mother, but Thou hast made it Thy throne. How much more honorable and venerable than the throne of a king is his mother."
St. Gregory Nazianzen calls her "the Mother of the King of the entire universe" as well as "Virgin Mother who brought forth the King of the entire world." - The Church Fathers On The Queenship Of Mary
The later Church Fathers are even more explicit in their wording as to Mary's Queenship as St. John Damascene calls her: "Queen, ruler, and lady".
Although not a Church Father, Catholic tradition sees Mary's Queenship in St. John's vision in the Book of Revelation 12:1-5:
“And a great sign appeared in heaven: A woman clothed with the sun, and the moon under her feet, and on her head a crown of twelve stars: And being with child, she cried travailing in birth, and was in pain to be delivered. And there was seen another sign in heaven: and behold a great red dragon, having seven heads, and ten horns: and on his head seven diadems: And his tail drew the third part of the stars of heaven, and cast them to the earth: and the dragon stood before the woman who was ready to be delivered; that, when she should be delivered, he might devour her son. And she brought forth a man child, who was to rule all nations with an iron rod: and her son was taken up to God, and to his throne.” - Biblical Basis of Mary's Royalty
From early Times New Roman Christians have believed, and not without reason, that she of whom was born the Son of the Most High received privileges of grace above all other beings created by God. He "will reign in the house of Jacob forever," "the Prince of Peace," the "King of Kings and Lord of Lords." And when Christians reflected upon the intimate connection that obtains between a mother and a son, they readily acknowledged the supreme royal dignity of the Mother of God.
Hence it is not surprising that the early writers of the Church called Mary "the Mother of the King" and "the Mother of the Lord," basing their stand on the words of St. Gabriel the archangel, who foretold that the Son of Mary would reign forever, and on the words of Elizabeth who greeted her with reverence and called her "the Mother of my Lord." Thereby they clearly signified that she derived a certain eminence and exalted station from the royal dignity of her Son.
So it is that St. Ephrem, burning with poetic inspiration, represents her as speaking in this way: "Let Heaven sustain me in its embrace, because I am honored above it. For heaven was not Thy mother, but Thou hast made it Thy throne. How much more honorable and venerable than the throne of a king is her mother." And in another place he thus prays to her: ". . . Majestic and Heavenly Maid, Lady, Queen, protect and keep me under your wing lest Satan the sower of destruction glory over me, lest my wicked foe be victorious against me."
St. Gregory Nazianzen calls Mary "the Mother of the King of the universe," and the "Virgin Mother who brought forth the King of the whole world," while Prudentius asserts that the Mother marvels "that she has brought forth God as man, and even as Supreme King."
And this royal dignity of the Blessed Virgin Mary is quite clearly indicated through direct assertion by those who call her "Lady," "Ruler" and "Queen."
In one of the homilies attributed to Origen, Elizabeth calls Mary "the Mother of my Lord." and even addresses her as "Thou, my Lady."
The same thing is found in the writings of St. Jerome where he makes the following statement amidst various interpretations of Mary's name: "We should realize that Mary means Lady in the Syrian Language." After him St. Chrysologus says the same thing more explicitly in these words: "The Hebrew word 'Mary' means 'Domina.' The Angel therefore addresses her as 'Lady' to preclude all servile fear in the Lord's Mother, who was born and was called 'Lady' by the authority and command of her own Son."
Moreover Epiphanius, the bishop of Constantinople, writing to the Sovereign Pontiff Hormisdas, says that we should pray that the unity of the Church may be preserved "by the grace of the holy and consubstantial Trinity and by the prayers of Mary, Our Lady, the holy and glorious Virgin and Mother of God."
The Blessed Virgin, sitting at the right hand of God to pray for us is hailed by another writer of that same era in these words, "the Queen[17a] of mortal man, the most holy Mother of God."
St. Andrew of Crete frequently attributes the dignity of a Queen to the Virgin Mary. For example, he writes, "Today He transports from her earthly dwelling, as Queen of the human race, His ever-Virgin Mother, from whose womb He, the living God, took on human form."
And in another place he speaks of "the Queen of the entire human race faithful to the exact meaning of her name, who is exalted above all things save only God himself."
Likewise St. Germanus speaks to the humble Virgin in these words: "Be enthroned, Lady, for it is fitting that you should sit in an exalted place since you are a Queen and glorious above all kings." He likewise calls her the "Queen of all of those who dwell on earth."
She is called by St. John Damascene "Queen, ruler, and lady," and also "the Queen of every creature." Another ancient writer of the Eastern Church calls her "favored Queen," "the perpetual Queen beside the King, her son," whose "snow-white brow is crowned with a golden diadem."
And finally St. Ildephonsus of Toledo gathers together almost all of her titles of honor in this salutation: "O my Lady, my Sovereign, You who rule over me, Mother of my Lord . . . Lady among handmaids, Queen among sisters."
The theologians of the Church, deriving their teaching from these and almost innumerable other testimonies handed down long ago, have called the most Blessed Virgin the Queen of all creatures, the Queen of the world, and the Ruler of all.
Please note that if Pope Pius XII had knowledge that ECFs like Polycarp, Ignatius, Irenaeus, Tertullian, and others, besides Origen, had written that Mary is Queen of heaven, then he would have cited them.