Ambo at San Lorenzo
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. 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.
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beauty in the twelfth, and then gradually fell out of use, until in the fourteenth century, when they were largely superseded by pulpits.
Under Pope Innocent IV (1243-54), the basilica of St Lawrence was renovated in the Cosmati style and the new choir features this grand ambo.