Although the modern building is from 1823, the basilica was founded by the Roman emperor
Constantine the Great over the burial place of
Paul of Tarsus, where it was said that, after the apostle's execution, his followers erected a memorial, called a
cella memoriae. This first basilica was consecrated by
Pope Sylvester in 324. In 386, Emperor
Theodosius I began erecting a much larger and more beautiful basilica with a nave and four aisles with a transept. It was probably consecrated around 402 by
Pope Innocent I. The work, including the mosaics, was not completed until
Leo I's pontificate (440–461). In the 5th century, it was larger than the
Old Saint Peter's Basilica. The Christian poet
Prudentius, who saw it at the time of emperor
Honorius (395–423), describes the splendours of the monument in a few expressive lines. Under Leo I, extensive repair work was carried out following the collapse of the roof on account of fire or lightning. In particular, the transept (i.e. the area around Paul's tomb) was elevated and a new main altar and presbytery were installed. This was probably the first time that an altar was placed over the tomb of Saint Paul, which remained untouched, but largely underground given Leo's newly elevated floor levels. Leo was also responsible for fixing the triumphal arch and for restoring a fountain in the courtyard (atrium). Under
Pope Gregory the Great (590–604), the main altar and presbytery were extensively modified. The pavement in the transept was raised and a new altar was placed above the earlier altar erected by
Leo I. The position was directly over Saint Paul's sarcophagus. In that period, there were two monasteries near the basilica: Saint Aristus's for men and Saint Stefano's for women. Masses were celebrated by a special body of clerics instituted by
Pope Simplicius. Over time, the monasteries and the basilica's clergy declined;
Pope Gregory II restored the former and entrusted the monks with the basilica's care. The basilica was damaged in an
earthquake on 29 April 801. Its roof collapsed, but was rebuilt by
Leo III. As it lay outside the
Aurelian Walls, the basilica was damaged in the 9th century during a
Saracen raid. Consequently,
Pope John VIII (872–882) fortified the basilica, the monastery, and the dwellings of the peasantry, forming the town of Johannispolis (Italian:
Giovannipoli) which existed until 1348, when
an earthquake totally destroyed it. In 937, when
Odo of Cluny came to Rome,
Alberic II of Spoleto, Patrician of Rome, entrusted the monastery and basilica to his congregation and Odo placed Balduino of
Monte Cassino in charge.
Pope Gregory VII was abbot of the monastery and in his time Pantaleone, a rich merchant of
Amalfi who lived in
Constantinople, presented the bronze doors of the
basilica maior, which were executed by Constantinopolitan artists; the doors are inscribed with Pantaleone's prayer that the "doors of life" may be opened to him.
Pope Martin V entrusted it to the monks of the
Congregation of Monte Cassino. It was then made an
abbey nullius. The abbot's jurisdiction extended over the districts of
Civitella San Paolo,
Leprignano, and
Nazzano, all of which formed parishes. The graceful
cloister of the monastery was erected between 1220 and 1241. From 1215 until 1964, it was the seat of the
Latin Patriarch of Alexandria.
Pope Benedict XIV undertook the restoration of the apse mosaic and the frescoes of the central nave, and commissioned the painter Salvatore Manosilio to continue the series of papal portraits, which at that time ended with
Pope Vitalian, who had reigned over a millennium earlier. On 15 July 1823, a workman repairing the copper gutters of the roof started a fire that led to the near-total destruction of this basilica, which, alone among all the churches of Rome, had preserved much of its original character for 1435 years. Marble salvaged from the burnt-out Saint Paul's was re-laid for the floor of
Santo Stefano del Cacco. In 1825,
Leo XII issued the encyclical
Ad plurimas encouraging donations for the reconstruction. A few months later, he issued orders that the basilica be rebuilt exactly as it had been when new in the fourth century, though he also stipulated that precious elements from later periods, such as the medieval mosaics and tabernacle, also be repaired and retained. These guidelines proved unrealistic for a variety of reasons and soon ceased to be enforced. The result is a reconstructed basilica that bears only a general resemblance to the original and is by no means identical to it. The reconstruction was initially entrusted to the architect Pasquale Belli, who was succeeded upon his death in 1833 by
Luigi Poletti, who supervised the project until his death in 1869 and was responsible for the lion's share of the work. Poletti also asked the scientist Angelo Secchi to design an automatic fire detection and extinguishing system, which was later removed. Many elements which had survived the fire were reused in the reconstruction. and that part of the basilica was then re-opened. The entire building was reconsecrated in 1854 in the presence of
Pope Pius IX and fifty cardinals. Many features of the building were still to be executed at that date, however, and work ultimately extended into the twentieth century. The quadriporticus looking toward the
Tiber was completed by the Italian Government, which declared the church a national monument. On 23 April 1891, an explosion at the gunpowder magazine at Forte Portuense destroyed the basilica's stained glass windows. On 31 May 2005,
Pope Benedict XVI ordered the basilica to come under the control of an
archpriest, naming
Archbishop Andrea Cordero Lanza di Montezemolo as its first archpriest. In 2024 the Governorate of Vatican City and the Heydar Aliyev Foundation have signed a significant agreement to restore the Basilica of Saint Paul Outside the Walls. On 23 October 2025, during
his state visit to the Holy See,
Charles III of the United Kingdom,
titular head of the
Church of England, accompanied by
his queen, visited the basilica, entering through its
Holy door. During an
ecumenical celebration presided over by the basilica's abbot,
Donato Ogliari, in presence of Cardinal Archpriest Harvey,
Archbishop of York and Primate of England Stephen Cottrell and the
Moderator of the General Assembly of the Church of Scotland Rosemary Frew, the King received the title of
Royal Confrater of the abbey. As a newly installed "brother", he then took a specially designed, throne-like
stall, bearing the
royal coat of arms and the Latin inscription from the
Gospel of John,
Ut unum sint - "That they may be one". The royal stall will be placed in the apse of the basilica, for future use by the king and his successors. ==Architecture and interior==