[Illustration: Balawat Gates, sheath and socket.
From _History of Art in Chaldaea and Assyria_, by permission of Chapman & Hall Ltd.]
The ancient Greek and Roman doors were either single doors ([Greek: monothyrai], _unifores_), double doors ([Greek: dithyrai], _bifores_ or _geminae_) or folding doors ([Greek: ptyches], _valvae_); in the last case the leaves were hinged and folded back one over the other. At Pompeii, in the portico of Eumachia, is a painting of a door with three leaves, the two outer ones of which were presumably hung, the inner leaf folding on one or the other; hinges connecting the folding leaves of a door have been found in Pompeii. In the tomb of Theron at Agrigentum there is a single four-panel door carved in stone. In the Blundell collection is a bas-relief of a temple with double doors, each leaf with five panels. Among existing examples, the bronze doors in the church of SS. Cosmas and Damiano, in Rome, are important examples of Roman metal work of the best period; they are in two leaves, each with two panels, and are framed in bronze. Those of the Pantheon are similar in design, with narrow horizontal panels in addition, at the top, bottom and middle. Two other bronze doors of the Roman period are in the Lateran Basilica.
The doors of the church of the Nativity at Bethlehem (6th century) are covered with plates of bronze, cut out in patterns: those of Sta Sophia at Constantinople, of the 8th and 9th century, are wrought in bronze, and the west doors of the cathedral of Aix-la-Chapelle (9th century), of similar manufacture, were probably brought from Constantinople, as also some of those in St Mark's, Venice.
Of the 11th and 12th centuries there are numerous examples of bronze doors, the earliest being one at Hildesheim, Germany (1015). Of others in South Italy and Sicily, the following are the finest: in Sant' Andrea, Amalfi (1060); Salerno (1099); Canosa (1111); Troja, two doors (1119 and 1124); Ravello (1179), by Barisano of Trani, who also made doors for Trani cathedral; and in Monreale and Pisa cathedrals, by Bonano of Pisa. In all these cases the hanging stile had pivots at the top and bottom. The exact period when the hinge was substituted is not quite known, but the change apparently brought about another method of strengthening and decorating doors, viz. with wrought-iron bands of infinite varieties of design. As a rule three bands from which the ornamental work springs constitute the hinges, which have rings outside the hanging stiles fitting on to vertical tenons run into the masonry or wooden frame. There is an early example of the 12th century in Lincoln; in France the metal work of the doors of Notre Dame at Paris is perhaps the most beautiful in execution, but examples are endless throughout France and England.