The Church commemorates the apparition of the sign of the Precious Cross over Jerusalem in AD 351.
The Precious Cross first appeared to Constantine the Great, with the triumphant emblem of victory: “In hoc signo vinces” (means “In this sign thou shalt conquer”). Today we celebrate another miraculous apparition that took place in Jerusalem around AD 346. At that time, the apparition took place during the reign of King Constantius, son of Constantine the Great, and Archbishop Cyril of Jerusalem.
The Precious Cross appeared in the sky over Jerusalem on the morning of May 7 during the Pentecost. The Holy and Life-giving Cross appeared in the sky, formed by a dazzling light, stretching from Golgotha to the Mount of Olives. This supernatural spectacle caused great admiration and emotion in all those present in Jerusalem. All the Christians ran to the church and wholeheartedly thanked and glorified God, who sanctified the wood of the Cross and made it a very powerful weapon of the struggling Christians against the devil and a support in every unexpected ordeal of life.
Source: Church of Cyprus