Who: The Blessed Virgin Mary, also known as Theotokos (Greek for “God-bearer”, “the one who gives birth to the one who is God”). The title Theotokos was decreed at the Council of Ephesus in 431 to counter the Nestorians who believed that Mary was only the mother of his human nature, and not his divine nature. Mary was affirmed as Theotokos because Jesus is both God and man. Theotokos is usually paraphrased as “Mother of God”, for whom this Feast honors.
What: A major Feast Day in honor of Mary’s divine motherhood to Christ, the second person of the Holy Trinity. The earliest records of such a Feast Day were first celebrated in the East shortly after the Council, and they indicate it was around Christmas. By the 7th century, the Feast was on January 1, called the Maternity of the Blessed Virgin Mary.