The feast day of the Assumption of Mary celebrates the Christian belief that God assumed the Virgin Mary into Heaven following her death, celebrated on 15 August. It's also called the Assumption of the Blessed Virgin Mary, the Dormition of the Most Holy Mother of God, or the Feast of the Assumption.
Assumption Day commemorates that when Mary, the mother of Jesus Christ, died, her body was not subjected to the usual process of physical decay but was “assumed” into heaven and reunited there with her soul. This holiday, which has been celebrated since the fourth century.
For centuries celebrations were held in the honor of the goddess Isis of the Sea, who was born on this day according to mythology. With the coming of Christianity church leaders decided that the easiest way to handle this pagan ritual was to simply change it into a Christian holiday, hence the introduction of Assumption Day came forth.
Like the Immaculate Conception, the Assumption was not always an official dogma of the Roman Catholic Church – not until Pope Pius XII ruled it so in 1950. It is regarded as the principal feast day of the Virgin Mother.
Symbolic images of the Virgin Mary and her assumption into heaven have been associated with the day. Blue is the color most often associated with the Virgin Mary. It symbolizes truth and clarity, and it is the color of the sky, which symbolizes heaven. The lily, which is a symbol of purity, chastity, and simplicity, is also associated with the Virgin Mary.