Ember days are the days at the beginning of the seasons ordered by
the Church as days of fast and abstinence. They were definitely
arranged and prescribed for the entire Church by Pope Gregory VII
(1073-1085) for the Wednesday, Friday, and Saturday after 13
December (S. Lucia), after Ash Wednesday, after Whitsunday, and
after 14 September (Exaltation of the Cross). The purpose of their
introduction, besides the general one intended by all prayer and
fasting, was to thank God for the gifts of nature, to teach men to
make use of them in moderation, and to assist the needy. The
immediate occasion was the practice of the heathens of Rome. The
Romans were originally given to agriculture, and their native gods
belonged to the same class. At the beginning of the time for seeding
and harvesting religious ceremonies were performed to implore the
help of their deities: in June for a bountiful harvest, in September for
a rich vintage, and in December for the seeding; hence their feriae
sementivae, feriae messis, and feri vindemiales. The Church, when
converting heathen nations, has always tried to sanctify any practices
which could be utilized for a good purpose. At first the Church in
Rome had fasts in June, September, and December; the exact days
were not fixed but were announced by the priests. The “Liber
Pontificalis” ascribes to Pope Callistus (217-222) a law ordering the
fast, but probably it is older. Leo the Great (440-461) considers it an
Apostolic institution. When the fourth season was added cannot be
ascertained, but Gelasius (492-496) speaks of all four. This pope
also permitted the conferring of priesthood and deaconship on the
Saturdays of ember week–these were formerly given only at Easter.
Before Gelasius the ember days were known only in Rome, but after
his time their observance spread. They were brought into England by
St. Augustine; into Gaul and Germany by the Carlovingians. Spain
adopted them with the Roman Liturgy in the eleventh century. They
were introduced by St. Charles Borromeo into Milan.