The biretta (Latin: biretum, birretum) is a square cap with three or four peaks or horns, sometimes surmounted by a tuft. Traditionally the three-peaked biretta is worn by Catholic clergy and some Anglican and Lutheran clergy. A four-peaked biretta is worn as an academic dress (but not liturgically) by those holding a doctoral degree from a pontifical faculty or pontifical university or faculty. Occasionally the biretta is worn by advocates in law courts, for instance, the advocates in the Channel Islands.
The biretta may be used by all ranks of the Latin Church clergy, including cardinals and other bishops to priests, deacons, and even seminarians (who are not clergy, since they are not ordained). Those worn by cardinals are scarlet red and made of silk. After the Second Vatican Council the ceremony of giving the galero to cardinals was replaced with giving the biretta. The biretta of a bishop is amaranth in color, while those worn by priests, deacons, and seminarians are black. The pope does not make use of the biretta.
The Tridentine Roman Missal rubrics on low Mass require the priest to wear the biretta while proceeding to the altar, to hand it to the server on arrival and to resume it when leaving. At solemn Mass the sacred ministers wear it also when seated.
Cardinals bear no tuft or “pom” (they are given their birettas and zucchettos by the Pope who elevated them in a ceremony named a consistory – they will form a line, and kneel before him when receiving them), bishops bear a purple pom, priests who have been appointed as prelates to certain positions within the Vatican wear a black biretta with red pom, diocesan priests and deacons wear a black biretta with or without a black pom. It is often asserted that seminarians are only entitled to wear a biretta without a pom-pom, but there would seem to be no formal ruling on this point. Priests in monastic and mendicant religious orders that have their own habits (Benedictines, Franciscans, Dominicans, etc.) do not generally wear birettas: in most circumstances, even liturgical, the monastic hood took the place of the biretta. Canons Regular generally do—for instance the canons of the Order of Prémontré wear a white biretta. Clerks Regular (that is, post-Renaissance religious orders primarily dedicated to priestly ministry, for instance the Jesuits and Redemptorists) generally wear a black biretta with no tuft. Other priests who belong to various forms of community life, as the Congregation of the Oratory of St. Philip Neri for instance, generally also wear birettas, but without a pom. The Institute of Christ the King Sovereign Priest uses black birettas with a blue pom.
The liturgical biretta has three peaks (four peaks however are the norm in Germany and the Netherlands), with the “peak-less” corner worn on the left side of the head. According to the 1913 Catholic Encyclopedia, “It was formerly the rule that a priest should always wear it in giving absolution in confession, and it is probable that the ancient usage which requires an English judge assume the ‘black cap’ in pronouncing sentence of death is of identical origin.”
The use of the biretta has not been abolished as a result of changes in the regulation of clerical dress and vesture following the Second Vatican Council and still remains the correct liturgical headgear for those in Holy Orders whilst “in choir”, but its use has been made optional. Its use is prevalent among bishops and cardinals, and less so among other clergy. Some priests wear it during outdoor services such as burials or processions and, as is intended, during the celebration of Mass and other liturgical services. The biretta is also worn by a priest, deacon, subdeacon, and bishop in attendance at a Mass offered according to the rubrics for the Roman Missal of 1962.
In the medieval university, the ceremony by which a new master or doctor received his degree included the birretatio, or imposition of the biretta. This was often given with a token book in recognition of the person’s scholarship. The academic biretta developed into various styles of academic headgear on the European continent and in the British Isles. Today some secular universities still use the term, if not the actual biretta, to name their academic cap.