This feast may represent a Christian adaptation of the pagan feast, Cervulus, integrating it with the donkey in the nativity story. In connection with the Biblical stories, the celebration was first celebrated in the 11th century, inspired by the pseudo-Augustinian "Sermo contra Judaeos" c. 6th century. In the second half of the 15th century, the feast disappeared gradually, along with the Feast of Fools, which was stamped out around the same time. It was not considered as objectionable as the Feast of Fools.
Practices
A girl and a child on a donkey would be led through town to the church, where the donkey would stand beside the altar during the sermon.
In detail
The preacher impersonates the Hebrew prophets whose Messianic utterances he works into an argument establishing the Divinity of Christ. Having confuted the Jews out of the mouths of their own teachers, the orator addresses himself to the unbelieving Gentiles— "Ecce, convertimur ad gentes." The testimony of Virgil, Nabuchodonosor, and the Erythraean Sibyl is eloquently set forth and interpreted in favour of the general thesis. As early as the eleventh century this sermon had taken the form of a metrical dramatic dialogue, the stage-arrangement adhering closely to the original. Additions and adaptations were gradually introduced. A Rouen manuscript of the 13th century exhibits twenty-eight prophets as taking part in the play. After Terce, the rubric directs, "let the procession move to the church, in the centre of which let there be a furnace and an idol for the brethren to refuse to worship." The procession filed into the choir. On the one side were seated Moses, Amos, Isaias, Aaron, Balaam and his Ass, Zachary and Elizabeth, John the Baptist and Simeon. The three Gentile prophets sat opposite. The proceedings were conducted under the auspices of Saint Augustine, whom the presiding dignitary called on each of the prophets, who successively testified to the birth of the Messiah. When the Sibyl had recited her acrostic lines on the Signs of Judgment, all the prophets sang in unison a hymn of praise to the long-sought Saviour. Mass immediately followed. In all this the part that pleased the congregation was the role of Balaam and the Ass; hence the popular designation of the Processus Prophetarum as the Feast of the Ass. The part of Balaam was soon dissociated from its surroundings and expanded into an independent drama. The Rouen rubrics direct that two messengers be sent by King Balaak to bring forth the prophet. Balaam advances riding on a gorgeously caparisoned ass. From the Chester pageant it is clear that the prophet rode on a wooden animal, since the rubric supposes that the speaker for the beast is "in asina". Then follows the scene in which the ass meets the angered angel and protests at length against the cruelty of the rider. Once detached from the parent stem, the Festum Asinorum branched in various directions. In the Beauvais13th century document the Feast of Asses is already an independent trope with the date and purpose of its celebration changed. At Beauvais the Ass may have continued his minor role of enlivening the long procession of Prophets. On the January 14, however, he discharged an important function in that city's festivities. On the feast of the Flight into Egypt the most beautiful girl in the town, with a pretty child in her arms, was placed on a richly draped ass, and conducted with religious gravity to St Stephen's Church. The Ass was stationed at the right of the altar, and the Mass was begun. After the Introit a Latin prose was sung. The first stanza and its French refrain may serve as a specimen of the nine that follow: Mass was continued, and at its end, apparently without awakening the least consciousness of its impropriety, the following direction was observed: This is the sole instance of a service of this nature in connection with the Feast of Ass. The Festum Asinorum gradually lost its identity, and became incorporated in the ceremonies of the Deposuit or united in the general merry-making on the Feast of Fools. The Processus Prophetarum, whence it drew its origin, survives in the Corpus Christi and Whitsun Cycles, that stand at the head of the modern English drama.