The Bishop's church had its prototype in the first Christian meeting places in Rome and was planned from two basic ideas,--the part of the Roman house which was devoted to early Christian service, and the growing exigencies of the ritual itself. At the very first of the Christian era, converts met in any room, but these little groups so soon grew to communities that a larger place was needed and the "basilica" of the house became the general and accepted place of worship. The "basilica" was composed of a long hall, sometimes galleried, and a hemicycle; and its general outline was that of a letter T. Into this purely secular building, Christian ceremonials were introduced. The hemicycle became the apse; the gallery, a clerestory; the hall, a central nave. Here the paraphernalia of the new Church were installed. The altar stood in the apse; and between it and the nave, on either side, a pulpit or reading-desk was placed. Bishop and priests sat around the altar, the people in the nave. This disposition of clergy, people, and the furniture of the sacred office is essentially that of the Cathedral of to-day. There were however many amplifications of the first type. The basilica form, T, was enlarged to that of a cross; and increasingly beautiful architectural forms were evolved. Among the first was the tower of the early Italian churches. This single tower was doubled in the French Romanesque, often multiplied again by Gothic builders, and in Byzantine churches, increased to seven and even nine domes. Transepts were added, and as, one by one, the arts came to the knowledge of the Middle Ages and the Renaissance, each was pressed into the service of the Cathedral builders. The interior became so beautiful with carvings, windows of marvellously painted glass, rich tapestries and frescoes, that the ritual seemed yearly more impressive and awe-inspiring. The old, squat exterior of early days was forgotten in new height and majesty, and the Cathedral became the dominant building of the city. Although the country was early christianised, and on the map of Merovingian France nearly all the present Cathedral cities of the Mediterranean were seats of Bishoprics, we cannot now see all the successive steps of the church architecture of the South. The main era of the buildings which have come down to us, is the XI-XIV centuries. Of earlier types and stages little is known, little remains. [Illustration: A NAVE OF THE EARLIER STYLE.--ARLES.]