The first Christian Emperor Constantine the Great and his mother, St. Helen, who found the True Cross. Celebrated on May 21st, this feast honors Constantine's legalization of Christianity and Helen's pilgrimage to the Holy Land. Their work established Christianity's place in the Byzantine Empire and preserved many holy sites.

The morning prayer service of the Orthodox Church, traditionally celebrated at dawn. Also called Orthros in Greek tradition, this service includes the reading of the Gospel, the Great Doxology, and numerous psalms and hymns. Matins prepares the faithful for the day and is often celebrated immediately before the Divine Liturgy on Sundays and feast days.