The oldest part of the Cathedral is the baptistery, and the date of its origin is unknown. Much of its character was lost in a restoration of the XVII century, but its old round form, the magnificent Roman columns of granite and green marble said to have been part of the Temple to Apollo, give it an atmosphere of dignity and an ancient charm that even the XVII century--so potent in architectural evil--was unable to destroy.
In 1060, after the destructive vicissitudes of the early centuries, Archbishop Rostaing d'Hyères issued a pastoral letter appealing to the Faithful to aid him in the re-building of a new Cathedral; and it may be reasonably supposed that the nave which is at present the south aisle, the baptistery, and the Cloisters were the buildings that were dedicated less than fifty years later. They are the only portions of the church which can be ascribed to so early a period, and with the low door of entrance, the single nave and the adjoining cloister-walk, they constitute the usual plan of XI century Romanesque. Considering this as the early church, in almost original form, it will be seen that the portal is a very interesting example of the Provençal use not only of Roman suggestion, but of the actual fragments of Roman art which had escaped the invader; that the south aisle, in itself a completed interior, bears a close resemblance to Avignon; and that the Cloister, although now very worn and even defaced, must have been one of the quaintest and most delicate, as it is one of the tiniest, in Provence. Three sides of its arcades support plain buildings of a later date; the fourth stands free, as if in ruin. Little coupled columns, some slenderly circular, some twisted, and some polygonal, rest on a low wall; piers, very finely and differently carved, are at each of the arcade angles; the little capitals of the columns were once beautifully cut, and even the surfaces of the arches have small foliated disks and rosettes and are finished in roll and hollow. Unfortunately, a very large part of this detail-work is so defaced that its subjects are barely suggested, some are so eaten away that they are as desolate of beauty as the barren little quadrangle; and the whole Cloister seems to have reached the brink of that pathetic old age which Shakespeare has described, and that another step in the march of time would leave it "sans everything."