What happened on September 14 ?

In ancient Greece, the first day of the Eleusinian Mysteries, during which the sacred objects were brought from Eleusis to Athens.

Roman Catholic Church - Triumph of the Cross (compare May 3, Finding of the Holy Cross).

Eastern Orthodox Church - Exaltation of the Cross, which commemorates the discovery of the (allegedly) original Christian cross in 326 by Helena, mother of Constantine, as well as the recovery from the Persians by Heraclius in 628.

Formerly, in the Roman Catholic and Anglican churches, the Wednesday, Friday and Saturday following 14 September were observed as one of the four sets of Ember days. In the Irish calendar they were known as Quarter tense.