The Feast of the Transfiguration is celebrated by various Christian communities in honor of the transfiguration of Jesus. The origins of the feast are less than certain and may have derived from the dedication of three basilicas on Mount Tabor. The feast was present in various forms by the 9th century, and in the Western Church was made a universal feast on 6 August by Pope Callixtus III to commemorate the raising of the siege of Belgrade (1456). In the Syriac Orthodox, Malankara Orthodox, Revised Julian calendars within Eastern Orthodoxy, Catholic, Old Catholic, and Anglican churches, the Feast of the Transfiguration is observed on 6 August. In the Armenian Apostolic Church, the Feast of the Transfiguration is observed on the fourteenth Sunday after Easter. In some Lutheran traditions preceding the reforms to the liturgy in the 1970s, the 6th of August was also observed as the Feast of the Transfiguration. In those Orthodox churches which continue to follow the Julian Calendar, August 6 falls on August 19 of the Gregorian Calendar. The Transfiguration is considered a major feast, numbered among the twelve Great Feasts in Byzantine Catholicism and Orthodoxy. In all these churches, if the feast falls on a Sunday, its liturgy is not combined with the Sunday liturgy, but completely replaces it. The transfiguration can also be celebrated at other points in the Christian calendar, sometimes in addition to the feast itself. In the ancient western lectionary, the Ember Saturday in Lent included the Transfiguration. In the Revised Common Lectionary, followed by some Lutherans, United Methodists, Anglicans, and others, the last Sunday in the Epiphany season (that immediately preceding Ash Wednesday) uses the Gospel account, which has led some churches without established festal calendars to refer to this day as "Transfiguration Sunday." In the Church of Sweden and the Church of Finland, the story is read on the seventh Sunday after Trinity, the eighth Sunday after Pentecost. Byzantine Catholic and Eastern Orthodox Churches In the Byzantine Catholic and Eastern Orthodox Churches, the Transfiguration falls during the Dormition Fast, but in recognition of the feast the fast is relaxed somewhat and the consumption of fish, wine and oil is allowed on this day. In the Byzantine view the Transfiguration is not only a feast in honor of Jesus, but a feast of the Holy Trinity, for all three Persons of the Trinity are interpreted as being present at that moment: