The feast originally commemorated the dedication of the
Martyrium, and was linked with the finding of the Cross shortly thereafter. Saint Helena reportedly found the Cross on September 14, 326. The feast entered the Western calendar in the seventh century after Emperor Heraclius recovered the cross from the Persians.
"Invention" (Finding) of the True Cross Beginning about the seventh century, the Gallican Church, celebrated the Feast of the Cross on May 3. The Feast of the "Invention of the True Cross" commemorates the recovery by the
Byzantine Emperor Heraclius, of a portion of the Holy Cross on 3 May 629, after it fell into the hands of the Persians. According to
Herbert Thurston: [T]he portion of the Holy Cross preserved in Jerusalem afterwards fell into the hands of the Persians, but was recovered and,...was solemnly brought back to Jerusalem on 3 May, 629. This day seems to have attracted special attention among Celtic liturgists in the West and, though disregarded in the East, has passed through Celtic channels (we meet it first in the Lectionary of Silos and in the Bobbio Missal) into general recognition under the mistaken title of "Invention of the Cross. The commemoration of the "Invention of the True Cross', particularly popular in the historical
Gallican Rite of the
Catholic Church. was kept by the Western Church on 3 May. ==Later developments==