Innocent III (1198-1216) ordered the creation of the large mosaic  in the apse (24 meters wide and 12 meters long), which at present looks much the same as it did when it was completed centuries ago. Later Pope Honorius III , called on another group of Venetian artists who had worked on the Basilica of Saint Mark in Venice to complete the team of mosaicists for the project.
Many artists contributed to its final construction. The Gothic baldachin, located right above the Papal Altar and the tomb, was realized by Arnolfo di Cambio ; while the decoration of the façade was done by Pietro Cavallini, the cloister by the Vassalletto family , and the monumental Candelabrum for the Paschal candle was created by Nicola D’Angelo and Pietro Vassalletto .
At that time the Basilica was universally known, not only as an important destination for pilgrimages but also as a chest of Paleo-Christian, Byzantine and Gothic artistic treasures.
1) The magnificent mosaic was restored between the 16th and 18th centuries and, after the fire partially destroyed it in the 19th century, it was repaired by using parts of the old tesserae. At present some original fragments, representing the heads of the Apostles, are exposed in the Permanent Exhibit Halls.
2) One may observe Pope Honorius III kneeling at Christ’s feet. Pope Paul VI referred to this image during his first address to the Bishops taking part in the Second Vatican Council on September 29, 1963: “The radiant royal majesty of Jesus emerges in the Pantocrator, just like in your Basilicas, Our Venerable Brethren of the Eastern and Western Churches. And We recognize Ourselves in the figure of Our Predecessor, Honorius III, in the magnificent mosaic of Saint Paul Outside-the-Walls, represented in adoration before Christ, a tiny figure bowed down to kiss Christ’s feet who, in His Greatness, is presiding over the assembly gathered in the Basilica, that is the Church”.
3) The Gothic canopy, rich and delicate at the same time (1285), with its pointed arches whose corner niches house the statues of Paul, Peter, Timothy and Bartholomew (the Abbot at that time), represents the initial expressions of a new figurative art. The canopy is sustained by four porphyry columns.
4) The cloister, adjacent to the transept on the south side, is considered the apex of the Cosmatesque School (workshop of the Vassaletto family at the beginning of the 13th century). This quad is composed of a series of four small columns, each one different from the other, smooth, ribbed, or twisted, all sustaining small round arches, surmounted by a marvelous architrave decorated by mosaics.
5) The Candelabrum of the Easter Candle has been present since the 10th century, near the bare altar during the Holy Saturday liturgy. The Candelabrum of Saint Paul is an exceptional example of the work done by the Roman marble artists between the end of the 12th century and the beginning of the 13th: scenes of the Passion and Resurrection are flanked by decorations with acanthus leaves and animals. One can observe the names of Nicola d’Angelo and Pietro Vassaletto to whom this work is attributed.