The Feast of the Holy Cross, which we celebrate today, September 14th, is traditionally kept to acknowledge three events: Saint Helena finding the true cross in 326 AD (she found it while on pilgrimage to Jerusalem); the dedication of churches built by Constantine on the site of the Holy Sepulchre and Mount Calvary; and the restoration of true cross to Jerusalem in 629 AD by the Byzantine emperor Heraclius—it had been taken away after Jerusalem fell to the Persian Emperor in 614 AD. While the authenticity of relics of the cross may be questionable for some, Holy Cross Day provides an opportunity for a celebration of Christ’s redeeming death on a cross for the sins of the whole world.
From the Book of Common Prayer:
O BLESSED Saviour, who by thy cross and passion hast given life unto the world: Grant that we thy servants may be given grace to take up the cross and follow thee through life and death; whom with the Father and the Holy Spirit we worship and glorify, one God, for ever and ever. Amen.