Exaltation of the Holy Cross

"Today's feast is one of the greatest feasts of the Eastern Churches. It is frequently mentioned in ecclesiastical writings and always has as its object the triumph of Christ, his resurrection, and the veneration of the holy cross, the sign of his victory over death. The feast of the Exaltation of the Holy Cross was first instituted in order to commemorate the dedication of the Church of the Resurrection on September 13, 335. The Emperor Constantine built this church and the one in Bethlehem and they are both in existence today.

The Church of the Resurrection had five naves and in the interior a circular structure covered by a dome which protected the sancturay of the sepulchre or tomb of Christ. The date of September 13 was chosen in order to supplant the pagan feast of the Temple of Jupiter in Rome.
The second historical event which is the source of our present feast was the return of the holy cross to Jerusalem under Emperor Heraclius. ...

On this day the Maronite Church celebrates the Rite of the Cross, which is a service of adoration of the cross, the sign of our salvation. This feast which comes at the end of the annual liturgical cycle is also directed toward the second coming of Christ, who carries his cross of light and triumph. It is this theme which is the object of the readings and prayers of the seven weeks which follow and which close the liturgical year.
Adoration and honor to the Cross of our Savior!
Glory and praise to Christ our God, for ever! Amen.

(Taken from the Synaxarion of the Prayer of the Faithful)