PALLIUM. — It is a white woolen band 4–6 cm wide, distinguished by six black silk crosses, worn around the shoulders with two ends hanging down, one over the chest and the other over the back; it is adorned with three jeweled brooches (aciculae) on the chest, back, and left shoulder.
It is a liturgical insignia of honor and jurisdiction, reserved to the pope and to metropolitan archbishops. Within three months of their consecration or confirmation, metropolitans must request the pallium from the pope; this obligation dates from the second half of the 9th century. The delivery or imposition of the pallium takes place in Rome by the first cardinal deacon; outside Rome, in the metropolitan see, by the appointed bishop after the solemn Mass and after the metropolitan archbishop has taken the oath of fidelity (since the 11th century, however, after the profession of faith). The metropolitan wears the pallium only at pontifical Masses in his own church and in those of his province on the days fixed by the Roman Pontifical (I, tit. XIV, n. 10), on the feasts of the Immaculate Conception and of St. Joseph, added by Leo XIII, and at ordinations, consecrations, etc. It is a personal insignia and cannot be lent to another; if an archbishop is transferred to another metropolitan see, he must request a new one. The pope, invested with supreme power and full jurisdiction, always wears it at solemn Masses and everywhere.
It is made from the wool of two white lambs blessed on January 23 in the basilica of St. Agnes (v. degli). At the first Vespers of SS. Peter and Paul, the new pallia are blessed by the pope and kept in a gilded silver casket near the Confession and tomb of St. Peter, from which they are delivered to metropolitans.
The earliest representations of the pallium already appear in the famous ivory of Trier, in a procession with relics (mid-5th century), and more clearly in the figure of Bishop Maximian in the mosaic of S. Vitale in Ravenna (first half of the 6th century), where it appears as a scarf draped over the shoulders, the two ends hanging from the left shoulder. From the mid-9th century the two ends began to hang down, fastened with two brooches, exactly in the middle of the chest and back; a third brooch secures it on the left shoulder. Later, instead of brooches, there was a fixed seam; the three brooches remained decorative. The two ends, originally of considerable length down to the knee, were shortened after the 15th century to the present form (from the 17th century). The embroidery of the pallium with crosses, already begun in the Ravenna mosaic, increased in the Carolingian era; in the Middle Ages (Innocent III) it was red in color. The pallium of Archbishop Clement Augustus of Cologne (d. 1761) had two black crosses and six red ones. Originally the pallium was considered proper to the pope; bishops and archbishops wore it only by his concession. This concession dates from the 6th century; Pope Symmachus granted the privilege to St. Caesarius of Arles in 513.
As to the origin of the pallium, T. Klauser recently follows the thesis of Duchesne, namely that it is an imperial indult; others derive it from the ancient mantle of philosophers similar to the toga contabulata folded over (Lorenzo Braun instead sees in it an imitation of the Greek omophorion (ὀμωφόριον), which in the West became the proper insignia of the pope alone, while for all the bishops of the East it was a liturgical insignia.