Biretta

The biretta descends from the pileus, the soft round cap of the medieval universities, which was worn by graduates and which stiffened over time. Pressing a soft cap flat produces ridges, the ridges were then built in as raised peaks, and by the sixteenth century the shape was fixed: a stiff square cap with three or four upstanding blades and, usually, a tuft or pompon at the crown. The same ancestor, developing along a different line, produced the academic mortarboard, so a parish priest and a doctor of divinity in procession are wearing two descendants of one hat.

Colour marks rank rather than season. Black is worn by priests and deacons, purple by bishops, scarlet by cardinals, and white by some communities of canons regular. Three peaks are the ordinary form for clergy and a fourth is associated in some usages with doctorates. The tuft is omitted on a cardinal's biretta.

It is not a liturgical vestment in the sense that a chasuble is. It belongs to choir dress and to the ordinary outdoor and processional clothing of a cleric, and it goes over the cassock and surplice rather than over the vestments proper. Its Byzantine equivalents, the kalimavkion and the klobuk, are cylindrical and are worn by monastics as well as by clergy.

A biretta is put on and taken off, repeatedly, and the rules for that were once as precise as the rules for anything else. It is worn in procession to and from the altar and while seated. It is removed on arrival at the altar, at the name of Jesus, at the Gloria Patri, and whenever the wearer stands to pray. A priest hearing confessions wears it. A preacher may wear it in the pulpit. Servers were trained to take it and hold it, and the small business of passing a cap at the right moment is one of the more visible skills of a well-drilled sanctuary.

Nothing after the Second Vatican Council abolished it. What happened was quieter: the 1969 instruction on the dress of prelates simplified choir dress considerably, the general mood ran against clerical distinctiveness, and the biretta fell out of use in most places within a decade without ever being forbidden. For a generation it was seen mainly at funerals and in photographs.

Its partial return since the 1990s has come chiefly from younger clergy in the Latin church and, in parallel, from Anglo-Catholic parishes, and it is generally understood as a deliberate signal rather than as an unremarkable habit. A hat that once meant nothing more than that its wearer was a cleric now means that its wearer has chosen to wear it.