Quote from EWTN...
The Assumption of the Blessed Virgin Mary - Feast: Aug. 15th
The Assumption is the oldest feast day of Our Lady, but we don't know how it first came to be celebrated.
Its origin is lost in those days when Jerusalem was restored as a sacred city, at the time of the Roman Emperor Constantine (c. 285-337). By then it had been a pagan city for two centuries, ever since Emperor Hadrian (76-138) had leveled it around the year 135 and rebuilt it as <Aelia Capitolina> in honor of Jupiter.
For 200 years, every memory of Jesus was obliterated from the city, and the sites made holy by His life, death and Resurrection became pagan temples.
After the building of the Church of the Holy Sepulchre in 336, the sacred sites began to be restored and memories of the life of Our Lord began to be celebrated by the people of Jerusalem. One of the memories about his mother centered around the "Tomb of Mary," close to Mount Zion, where the early Christian community had lived.
On the hill itself was the "Place of Dormition," the spot of Mary's "falling asleep," where she had died. The "Tomb of Mary" was where she was buried.
At this time, the "Memory of Mary" was being celebrated. Later it was to become our feast of the Assumption.
For a time, the "Memory of Mary" was marked only in Palestine, but then it was extended by the emperor to all the churches of the East. In the seventh century, it began to be celebrated in Rome under the title of the "Falling Asleep" ("Dormitio") of the Mother of God.
Soon the name was changed to the "Assumption of Mary," since there was more to the feast than her dying. It also proclaimed that she had been taken up, body and soul, into heaven. [continue reading at EWTN]
Julie @ Connecticut Catholic Corner