While this feast would fit better during Lent, it is placed here to commemorate several historical events linked to the True Cross.
The Feast of the Exaltation of the Holy Cross may appear at first glance to be a strange celebration on September 14. It is entirely removed from the season of Lent and located near the end of Ordinary Time.
Why is that?
The feast dates back to at least the 7th century, though it was likely celebrated even before that. Originally it was a day to celebrate two different historical events linked to the True Cross of Jesus Christ.
Finding of the cross by St. Helena
According to various legends, in the 4th century St. Helena was inspired by God to travel to the Holy Land in search of the true cross of Jesus Christ.
After much effort, Helena discovered the cross due to its miraculous nature.
It is believed that Constantine built the basilica of the Holy Sepulchre after this finding of the True Cross, and the church was consecrated on September 14, 335.
Recovery of the cross from Persia
Around 615 a Persian king captured Jerusalem and carried off the relic of the true cross of Jesus Christ that had been discovered by St. Helena. It stayed with the Persians for roughly 14 years, until the Byzantine Emperor Heraclius came and defeated their armies.
Heraclius found the relic of Jesus’ cross still preserved and returned it to Jerusalem.
Eventually a separate feast was established to commemorate the Finding of the True Cross (May 3), and September 14 was preserved to celebrate the recovery of the cross from the Persians.
Currently the feast is more focused on reflecting on the cross of Jesus Christ and its role in salvation history.