The Catholic Church, the Eastern Orthodox Church, the Anglican Communion, and a number of Protestant denominations, celebrate the Feast of the Exaltation of the Cross on September 14, the anniversary of the dedication of the Church of the Holy Sepulchre.
According to legends that spread widely throughout Western Europe, the True Cross was discovered in 326AD by Saint Helena, the mother of the Roman Emperor Constantine the Great, during a pilgrimage she made to Jerusalem. The Church of the Holy Sepulchre was then built at the site of the discovery, by order of Helena and Constantine. The church was dedicated nine years later, with a portion of the cross placed inside it. Other legends explain that in 614AD, that portion of the cross was carried away from the church by the Persians, and remained missing until it was recaptured by the Byzantine Emperor Heraclius in 628AD. Initially taken to Constantinople, the cross was returned to the church the following year.
The date of the feast marks the dedication of the Church of the Holy Sepulchre in 335AD. This was a two-day festival: although the actual consecration of the church was on September 13, the cross itself was brought outside the church on September 14 so that the clergy and faithful could pray before the True Cross, and all could come forward to venerate it.