The publicly stated belief in Mary’s bodily Assumption into Heaven goes back at least to the sixth century, when St. Gregory of Tours wrote that the Lord Jesus came to earth at the end of Mary’s life and commanded that her holy body “be taken in a cloud into Paradise where now, rejoined to the soul, it rejoices with the Lord’s chosen ones, and is in the enjoyment of the good of an eternity that will never end.”
The dogma of the Assumption was never in doubt, but after Pope Pius IX defined the Immaculate Conception in 1854, Rome was inundated over many decades with literally millions of requests for a similar definition of the Assumption. Pope Pius XII answered those petitions on November 1, 1950, when he solemnly declared it to be “a dogma divinely revealed: that the Immaculate Mother of God, Mary ever Virgin, on the completion of her earthly life, was taken up to heavenly glory both in body and soul.”
The reasoning behind the Church’s belief is that since Mary was free from all sin, and the corruption of the body is a cons4equence of sin, she did not suffer the decay of the grave. Furthermore, since it was Mary’s body that brought the Savior into the world, her body should share in His bodily glorification.
The Church has never formally stated whether Mary died, but saints and holy writers have said that she underwent death. St. John Damascene, in the eight century, referred to an “ancient and most truthful tradition” that Mary did die and was placed in a coffin in the Garden of Gethsemani. After three days of singing and chanting by angels, the coffin was opened, but the Apostles “were unable anywhere to find her most lauded body.”
It is striking that there has never been any bodily relics of Mary, nor any attempt to identify her tomb This seems to be a case where Tradition was from the beginning consistent and unanimous. The church believes that Mary died at the age of 57.
Pope Pius XII, in his proclamation of her Assumption, said that our Lady did experience death, but that God preserved her “from the corruption of the tomb.” The Eastern Church celebrates the Feast of the Dormition (Falling Asleep) of Mary on August 14th, the day before the Feast of the Assumption