From the 14th century on, the tradition of Jubilees attracted pilgrimages to the tomb of the Apostle, and the Popes took advantage of those occasions to undertake important works. Boniface IX (1389-1405), and later Martin V (1417-1431), exhorted the faithful to make donations to realize these projects, granting them indulgences tied to their prayer and penance.
Gregory XIII added a balustrade around the tomb for the Jubilee of 1575. Clement VIII built the high altar for the Jubilee of 1600, while in 1625 Urban VIII transformed the chapel of St Lawrence by Carlo Maderno .
For the Jubilee year of 1725, Benedict XIII commissioned Antonio Canevari to construct a new portico, demolishing the ancient vestibule and adding the chapel of the Crucifix (or Blessed Sacrament) with the “miraculous” Crucifix, which was done in polychrome wood  by Tino di Camaino from Siena (14th century). Here one can also admire a 13th century mosaic icon and a touching relic-statue of Saint Paul made of polychrome wood which bears traces of evidence of the fire of 1823.
The altars and the chapels which open onto the transept make the Basilica a witness to Baroque art .
1) At the present time the monks celebrate lauds, vespers and choral mass here.
2) St Bridget reported having seen the face of Christ turn toward her while she was praying at the foot of this Crucifix in 1370. He offered her words of encouragement in founding a religious community. A statue of the saint was later placed in the Chapel. Another founder of a religious order, St. Ignatius of Loyola, professed his vows on August 22, 1541 before the 13th century mosaic icon which is also held in this Chapel
3) The Altar of the Conversion of Saint Paul, attributed to Camuccini and located in the apse of the left transept, recalls the fundamental experience of the internal conversion of the Apostle to the Gentiles. It is surrounded by the statues of St. Gregory the Great and St. Bernard. The altar of the Assumption, next to the right transept holds the copy of the mosaic of the coronation of the Virgin Mary, by Giulio Romano (1492). In the right transept lies the chapel of Saint Benedict, dedicated to the Monastic Order which for centuries has celebrated in the Basilica. It contains a homonym statue (a magnificent restoration of which was recently carried out).