The feast of the Exaltation of the Holy Cross celebrates two historical events: the discovery of the True Cross by Saint Helena, and the dedication in 335 of the basilica and shrine built on Calvary by Constantine, which marks the site of the Crucifixion.However the feast, more than anything else, is a celebration and commemoration of God's greatest work: his salvific death on the Cross and His Resurrection, through which death was defeated and the doors to Heaven opened.