The medieval Catholic Church forbade the eating of meat on religious days, and, in the seventh century, the number of these days was dramatically expanded. The Lenten fast, a custom started in the fourth century, was increased to forty days, and in addition all Fridays, the day of Christ’s crucifixion, were included. In all, about half the days of the year became “lean” days, and food prohibitions for these days were strictly enforced. Under English law the penalty for eating meat on Friday was hanging.
