What is the Sub Tuum Praesidium?
Sub Tuum Praesidium — 'Beneath Thy Protection' or 'We Fly to Thy Patronage' — is the oldest known prayer to the Blessed Virgin Mary still in continuous use. It asks her not to despise the petitions of her children in their necessities, but to deliver them from all dangers. It is the Church's most ancient Marian cry for help.
How old is this prayer?
Astonishingly old. A Greek papyrus fragment of the prayer — Papyrus 470, held at the John Rylands Library in Manchester — has been dated by paleographers to the third century, meaning it predates the Council of Nicaea and even the legalization of Christianity. The faithful have prayed these words, in Greek and Latin and a hundred vernaculars, for some seventeen centuries.
Where is the Sub Tuum Praesidium used in the Liturgy?
The Sub Tuum is one of the Marian antiphons of the Roman Breviary and appears in the Liturgy of the Hours throughout the year. It is also recited at moments of particular need, such as in the prayers of consecration to Mary, in times of national or ecclesial danger, and in the final commendation of the dying.
Why does this prayer call Mary 'Theotokos' / 'Dei Genetrix'?
The Latin Dei Genetrix translates the Greek Theotokos — 'God-bearer' or 'Mother of God.' That this title appears in a third-century prayer is striking historical evidence that the early Church already addressed Mary as the Mother of God, more than a century before the Council of Ephesus formally defined the doctrine in 431. The faithful had been praying what the Council would later confess.