This antiphon received the name either because it was sung on the steps of the altar or while the deacon was mounting the steps of the ambo for the reading or singing of the Gospel.
Some early ambones are found in Ravenna, and in the south of Italy are many fine examples; the epistle ambo in the cathedral at Ravello (1130), which is perhaps the earliest, shows a Scandinavian influence in the design of its mosaic inlay, an influence which is found in Sicilian work and may be a Norman importation.
The position of the ambo was not absolutely uniform; sometimes in the central point between the sanctuary and the nave, sometimes in the middle of the church, and sometimes at one or both of the sides of the chancel.
The cathedral (dedicated to St Nicholas the Pilgrim, a Greek assassinated at Trani in 1094 and canonized by Urban II.), on a raised open site near the sea, was consecrated, before its completion, in 1143; it is a basilica with three apses, a large crypt and a lofty tower, the latter erected in1230-1239by the architect whose name appears on the ambo in the cathedral of Bitonto, Nicolaus Sacerdos.
In the epistle ambo at Salerno and the gospel ambones at Cava and San Giovanni del Toro in Ravello, the columns support segmental arches carrying the ambones; the epistle ambo at Ravello and all those in Rome are raised on solid marble bases.
The gospel and epistle are still read from the ambo in the Ambrosian rite at Milan.
The two ambones in the cathedral of Salerno, which are different in design, are magnificent in effect and are enriched with sculpture as well as with mosaic. In the gospel ambo in the cathedral of Ravello (1272), and also in that of the convent of the Trinita della Cava near Salerno, the spiral columns inlaid with mosaic stand on the backs of lions.
The inconvenience of having a single ambo led to the substitution of two separate ambones, between which these various functions were divided, one on the south side of the chancel being for the reading of the gospel, and one on the north for reading the epistle.
Basilica with a vaulted portico and a nave and two aisles begun in 1103, a mosaic pavement in the Cosmatesque style, a good ambo resting on columns and decorated with mosaics showing traces of Moorish influence, a Paschal candelabrum, and an organ gallery of similar style.