Feast of the Dormition (or Assumption) of Mary. That’s Jesus’ mum, the Theotokos* (which is Greek) (the word, not the woman; she was a Palestinian Jew)—not one of those other Marys. Here follows the story of the Dormition as it is told in the Orthodox world (in my sources).
The Theotokos was in Jerusalem when she was told by the Archangel Gabriel that her end was near. (Actually she was at Golgotha, which was right outside Jerusalem, but you get the idea.) She went home and prayed that she might see the Apostle John one last time. The Holy Spirit whisked him up and deposited him in the house just as a voice from heaven added the “Amen” to the end of her prayer.
Before you could say, “The Catholics celebrate this day also, calling it ‘the Assumption,’ and we’ll get to that,” the disciples were all gathered, and were asking John what was going on. He of course told them that the Mother of God was about to take her leave. They all rushed into her chamber (one source insists their number was “impossible to count,” so you have to imagine her chamber was larger on the inside than it was on the outside), and told her about the rather unusual mode of transportation they took to get there (you have to remember, this was before regularly scheduled airline service was introduced in that part of the world). While they were standing there talking, the Apostle Paul and some of his gang (including Timothy) landed and, bypassing baggage claim, came straight to her bedside.
Then she called them all by name and blessed them, and at exactly 9:00 a.m. (same time as (St.) Peter’s sermon on Pentecost (Acts 2), if you recall, in which tongues of fire came down from heaven), a bright light filled the room and the Lord Himself came down from heaven, with angels and archangels and a handful of forefathers and prophets. Mary rose to greet her Son with a few bars of her hymn, “My soul doth magnify the Lord,” and with joy she surrendered her soul. The angels sang a lovely hymn that started with the words Gabriel said to her all those years ago (q.v.). Then with much singing and clamor and rejoicing and heavenly light and such-like, the whole entourage took off for Heaven, leaving the disciples with our lady’s body, which they reverenced, and carried in procession to the Garden of Gethsemane.
After much weeping, lamenting, wailing, crying, and the like, they laid her sweet-smelling body in the tomb, and kept watch for three days. On the third day, the Apostle Thomas turned up—he was flying in from India, you understand, and perhaps had had a longish layover somewhere along the way (Babylon?). “Late again,” he said sadly. “Can I at least see her body, and, like, kiss her hand or something?” The other Apostles looked at each other, shrugged, and opened the tomb. The blessed Virgin was not there! Only her clothes remained. The Apostles then knew that her body had been taken up or “assumed” into Heaven. She has undergone the resurrection of the body that all of us (or at least the dead ones) will experience on the last day.
The feast of the Assumption or Dormition has been celebrated since at least the fourth or fifth century (depending on whom you ask) on both sides of the Adriatic. Pope Pius XII pronounced as dogma, in 1950, that “the Immaculate Mother of God, the ever Virgin Mary, having completed the course of her earthly life, was assumed body and soul into heavenly glory.” (Or something in Latin that translates to roughly that.) As the dogma does not specify, some pious Catholics believe she died first, and some that she was assumed into heaven alive (like Elijah). Interestingly (well, I find it interesting), both the feast and the belief in the bodily assumption of Mary came to Rome by way of Gaul.