The half dome of the central apse has a colossal halflength figure of Christ, with a seated Virgin and Child below; the other apses have full-length colossal figures of St Peter and St Paul.
On his death in 1035 Archbishop Poppo converted the gate into two churches, one above the other, but all the additions except the apse have now been removed.
The two campanili flanking the apse at each end of the side aisle are the oldest example of this architectural arrangement.
Archbishop Poppo and his successors in the i 1 th and 12th centuries extended the cathedral westwards and added an apse at each end.
The exterior is uninteresting, and the church lost both atrium and apse in the 16th century.
The Romanesque choir and apse belong to the 11th century, the rest of the interior is contemporary with the facade.
In the centre of this court stands the catholicon or conventual church, a square building with an apse of the cruciform domical Byzantine type, approached by a domed narthex.
The apse is built over a canal.
There is a remarkably perfect Romanesque church, with aisles, eastern apse and ambulatory, at Varnhem in Skaraborg Lan, and there are a few village churches of the same period in this district and in Skane.
The relics of the two Marks, who are said to have been buried at Saintes-Maries, are bestowed in the upper storey of the apse of the fortress-church, a remarkable building of the 12th century with crenelated and machicolated walls.