A mountain or elevation
Ambo (pl. Ambos, or Ambones), a word of Greek origin, supposed to signify a mountain or elevation; at least Innocent III so understood it, for in his work on the Mass (II.I, xxxiii), after speaking of the deacon ascending the ambo to read the Gospel, he quotes the following from Isaias (xl, 9): "Get thee up upon a high mountain, thou that bringest good tidings to Sion: lift up thy voice with strength". And in the same connection he also alludes to Our Blessed Lord preaching from a mountain: "He went up into a mountain—and opening his mouth he taught them" (Matt., v, 1, 2). An ambo is an elevated desk or pulpit from which in the early churches and basilicas the Gospel and Epistle were chanted or read, and all kinds of communications were made to the congregation; and sometimes the bishop preached from it, as in the case of St. John Chrysostom, who, Socrates says, was accustomed to mount the ambo to address the people, in order to be more distinctly heard (Eccl. Hist., VI, v). Originally there was only one ambo in a church, placed in the nave, and provided with two flights of steps; one from the east, the side towards the altar; and the other from the west. From the eastern steps the subdeacon, with his face to the altar, read the Epistles; and from the western steps the deacon, facing the people, read the Gospels. The inconvenience of having one ambo soon became manifest, and in consequence in many churches two ambones were erected. When there were two, they were usually placed one on each side of the choir, which was separated from the nave and aisles by a low wall. An excellent example of this arrangement can still be seen in the church of St. Clement at Rome. Very often the gospel ambo was provided with a permanent candlestick; the one attached to the ambo in St. Clement's is a marble spiral column, richly decorated with mosaic, and terminated by a capital twelve feet from the floor.
Ambones are believed to have taken their origin from the raised platform from which the Jewish rabbis read the Scriptures to the people, and they were first introduced into churches during the fourth century, were in universal use by the ninth, reaching their full development and artistic beauty in the twelfth, and then gradually fell out of use, until in the fourteenth century, when they were largely superseded by pulpits. In the Ambrosian Rite (Milan) the Gospel is still read from the ambo. They were usually built of white marble, enriched with carvings, inlays of colored marbles, Cosmati and glass mosaics. The most celebrated ambo was the one erected by the Emperor Justinian in the church of Sancta Sophia at Constantinople, which is fully described by the contemporary poet, Paulus Silentiarius in his work peri ktismaton. The body of the ambo was made of various precious metals, inlaid with ivory, overlaid with plates of repouss5 silver, and further enriched with gildings and bronze. The disappearance of this magnificent example of Christian art is involved in great obscurity. It was probably intact down to the time of the taking of Constantinople by the Crusaders in 1203, when it was largely shorn of its beauty and wealth. In St. Mark's, at Venice, there is a very peculiar ambo, of two stories; from the lower one was read the Epistle, and from the upper one the Gospel. This form was copied at a later date in what are known as "double-decker" pulpits. Very interesting examples may be seen in many of the Italian basilicas; in Ravenna there are a number of the sixth century; one of the seventh at Torcello; but the most beautiful are in the Roman churches of St. Clement, St. Mary in Cosmedin, St. Lawrence, and the Ara Coeli.