St. John is commemorated on 27 December, which he originally shared with St. James the Greater. At Rome the feast was reserved to St. John alone at an early date, though both names are found in the Carthage Calendar, the Hieronymian Martyrology, and the Gallican liturgical books. The "departure" or "assumption" of the Apostle is noted in the Menology of Constantinople and the Calendar of Naples (26 September), which seems to have been regarded as the date of his death. The feast of St. John before the Latin Gate, supposed to commemorate the dedication of the church near the Porta Latina, is first mentioned in the Sacramentary of Adrian I (772-95).
Early Christian art usually represents St. John with an eagle, symbolizing the heights to which he rises in the first chapter of his Gospel. The chalice as symbolic of St. John, which, according to some authorities, was not adopted until the thirteenth century, is sometimes interpreted with reference to the Last Supper, again as connected with the legend according to which St. John was handed a cup of poisoned wine, from which, at his blessing, the poison rose in the shape of a serpent. Perhaps the most natural explanation is to be found in the words of Christ to John and James "My chalice indeed you shall drink" (Matthew 20:23).
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Here is some additional information I found about John... also known as John the one whom Christ loved.
