The obligation of observing this Lent, which, though introduced so imperceptibly, had by degrees acquired the force of a sacred law, began to be relaxed, and the forty days from St. Martin's day to Christmas was reduced to four weeks. We have seen that this fast began to be observed first in France; but thence it spread into England, as we find from Venerable Bede's history; into Italy, as appears from a diploma of Astolphus, king of the Lombards, dated 753; into Germany, Spain, &c., of which the proofs may be seen in the learned work of Dom Martène, On the ancient rites of the Church. The first allusion to Advent's being reduced to four weeks is to be found in the ninth century, in a letter of Pope St. Nicholas I to the Bulgarians. The testimony of Ratherius of Verona, and of Abbo of Fleury, both writers of the tenth century, goes also to prove that, even then, the question of reducing the duration of the Advent fast by one-third was seriously entertained. It is true that St. Peter Damian, in the eleventh century, speaks of the Advent fast as still being for forty days; and that St. Louis, two centuries later, kept it for that length of time; but as far as this holy king is concerned, it is probable that it was only his own devotion which prompted him to this practice.
The discipline of the Churches of the west, after having reduced the time of the Advent fast, so far relented, in a few years, as to change the fast into a simple abstinence; and we even find Councils of the twelfth century, for instance Selingstadt in 1122, and Avranches in 1172, which seem to require only the clergy to observe this abstinence. The Council of Salisbury, held in 1281, would seem to expect none but monks to keep it. On the other hand (for the whole subject is very confused, owing, no doubt, to there never having been any uniformity of discipline regarding it in the western Church), we find Pope Innocent III, in his letter to the bishop of Braga, mentioning the custom of fasting during the whole of Advent, as being at that time observed in Rome; and Durandus, in the same thirteenth century, in his Rational on the Divine Offices, tells us that, in France, fasting was uninterruptedly observed during the whole of that holy time.
This much is certain, that, by degrees, the custom of fasting so far fell into disuse, that when, in 1362, Pope Urban V endeavoured to prevent the total decay of the Advent penance, all he insisted upon was that all the clerics of his court should keep abstinence during Advent, without in any way including others, either clergy or laity, in this law. St. Charles Borromeo also strove to bring back his people of Milan to the spirit, of not the letter, of ancient times. In his fourth Council, he enjoins the parish priests to exhort the faithful to go to Communion on the Sundays, at least, of Lent and Advent; and afterwards addressed to the faithful themselves a pastoral letter, in which, after having reminded them of the dispositions wherewith they ought to spend this holy time, he strongly urges them to fast on the Mondays, Wednesdays, and Fridays, at least, of each week in Advent. Finally, Pope Benedict XIV, when archbishop of Bologna, following these illustrious examples, wrote his eleventh Ecclesiastical Institution for the purpose of exciting in the minds of his diocesans the exalted idea which the Christians of former times had of the holy season of Advent, and of removing an erroneous opinion which prevailed in those parts, namely, that Advent concerned religious only and not the laity. He shows them that such an opinion, unless it be limited to the two practices of fasting and abstinence, is, strictly speaking, rash and scandalous, since it cannot be denied that, in the laws and usages of the universal Church, there exist special practices, having for their end to prepare the faithful for the great feast of the birth of Jesus Christ.