Peerage robes are worn in the United Kingdom by peers and are of two varieties for two occasions: Parliament robes, worn on ceremonial occasions in the House of Lords, and Coronation robes, worn in the House of Lords at coronations of monarchs. Peers wear a robe differentiated by features identifying their rank.
Since the early Middle Ages, robes have been worn as a sign of nobility. At first, these seem to have been bestowed on individuals by the monarch or feudal lord as a sign of special recognition; but in the fifteenth century the use of robes became formalised with peers all wearing robes of the same design, though varied according to the rank of the wearer.
Two distinct forms of robe emerged, and these remain in current use: one is worn for parliamentary occasions (such at the State Opening of Parliament), the other is generally worn only at coronations. (Formerly, new peers were invested with their coronation robe by the monarch, but this Investiture ceremony has not taken place since 1621.)
Coronets are worn with the Coronation robe; the robes and coronets used at Elizabeth II's coronation in 1953 cost about £1,250 (roughly £31,500 in present-day terms). (Peers under the rank of an Earl, however, were allowed in 1953 to wear a cheaper "cap of estate" in place of a coronet, as were peeresses of the same rank, for whom a simpler robe was also permitted (a one-piece gown with wrap-around fur cape, designed by Norman Hartnell).
The Parliament robe of a peer is a full-length garment of scarlet wool with a collar of white miniver fur. It is closed at the front with black silk satin ribbon ties (except for a short slit at the neck down half the length of the robe) but open from the shoulder on the right-hand side. (The opposite side is usually tied up with a ribbon to free the left arm). The back is cut long, as a train, but this is usually kept hooked up inside the garment. Miniver bars (edged with gold oak-leaf lace) on the right-hand side of the robe indicate the rank of the wearer: 4 for a duke, 3½ for a marquess, 3 for an earl, 2½ for a viscount, and 2 for a baron. Today the principal supplier of such robes is the London tailor Ede & Ravenscroft, founded in 1689. These robes are worn by peers at their Introduction to the House of Lords as well as at the State Opening of Parliament. They are also worn by Lords Commissioners when representing the Queen. They are directed to be worn 'when the peers attend as a body a church service or other ceremony'; however in the twentieth century they were only twice worn outside Parliament: at the Investitures of the Prince of Wales in 1911 and 1969. The Parliament robe is only worn by Peers who are sworn members of the House of Lords, and the robe is the same for female peers as for males. (Unlike the Coronation robe, there is no equivalent garment for the wives of peers to wear.)