Following the Baptism of the Lord, Saint John the Baptist was locked up in prison by Herod Antipas, the Tetrarch (ruler of one fourth of the Holy Land) and governor of Galilee. (After the death of king Herod the Great, the Romans divided the territory of Palestine into four parts, and put a governor in charge of each part. Herod Antipas received Galilee from the emperor Augustus).
The prophet of God John openly denounced Herod for having left his lawful wife, the daughter of the Arabian king Aretas, and then instead cohabiting with Herodias, the wife of his brother Philip (Luke 3:19-20). On his birthday, Herod made a feast for dignitaries, the elders and a thousand chief citizens. Salome, the daughter of Herod, danced before the guests and charmed Herod. In gratitude to the girl, he swore to give her whatever she would ask, up to half his kingdom.
The girl on the advice of her wicked mother Herodias asked that she be given the head of John the Baptist on a platter. Herod became apprehensive, for he feared the wrath of God for the murder of a prophet, whom earlier he had heeded. He also feared the people, who loved the holy Forerunner. But because of the guests and his careless oath, he gave orders to cut off the head of Saint John and to give it to Salome.
The Beheading of Saint John the Baptist, a Feast day established by the Church, is also a strict fast day because of the grief of Christians at the violent death of the saint. In some Orthodox cultures pious people will not eat food from a flat plate, use a knife, or eat food that is round in shape on this day.