History and Architecture of St. Peter's Basilica

Historical Context: Rome and the Early Christians

• Emperor Nero and the Fire of 64 CE: Following the Great Fire of Rome in $64\,CE$, Emperor Nero initiated a period of Christian persecution.

• Execution of Apostles: During this period of persecution, both St. Peter and St. Paul were executed in Rome.

• The Martyrdom of St. Peter:

  • Location: St. Peter was executed in Nero’s Circus (Circus Neronis), situated in the area of the Vatican hill.

  • Method of Execution: He was sentenced to die on the cross.

  • Specific Request: St. Peter requested to be crucified with his head down towards the ground. He believed he was not worthy to die in the same manner as Jesus (facing the sky).

The Circus of Nero (Circus Neronis)

• Site Significance: The circus was located in the Vatican area where the Temple of St. Peter (Teplum D. Petri) stands today.

• The Vatican Obelisk:

  • The obelisk standing in the circus was an exceptional work brought from Alexandria to Rome by Augustus (or Caligula, according to different accounts).

  • It was originally placed in the center of the circus (the spina) and later moved to the center of St. Peter’s Square by Pope Sixtus V in $1586$.

  • In ancient times, it was popularly believed to house the ashes of Julius Caesar within its gilded base or top ornament.

The Old Basilica of Constantine the Great

• Transition from Burial Ground to Basilica: The area where St. Peter was buried became a Christian burial site during Ancient Roman times.

• Constantine’s Construction: Emperor Constantine built a church directly ON TOP of the burial ground, founding the first Basilica of Saint Peter’s.

• Timeline of Construction:

  • Start Date: Construction began between $318\,CE$ and $322\,CE$.

  • Duration: The project took approximately $40$ years to complete.

• Historical Importance: Over the next twelve centuries, this church gained immense significance, eventually serving as a primary site of pilgrimage in Rome.

• Artistic Depiction: The "Fire of Borgo" scene in the Rooms of Raphael (Vatican) depicts aspects of the historical area.

• Restoration Archaeology: H.W. Brewer (1891) and other authorities have provided restored views of the Old St. Peter's as it appeared around the year $1450\,(MCCCCL)$.

The New Basilica and Major Architects

• The Demolition Order: In $1506$, Pope Julius II ordered the demolition of the Old Basilica to make way for a new, grander structure.

• Involved Architects (1505–1628): Virtually every significant architect of the era contributed to the planning, building, or decorating of the new basilica.

• Key Transitions in Design:

  • Donato Bramante (First Architect): Proposed a plan based on a Greek cross (Renaissance style).

  • Michelangelo Buonarroti: Also utilized a Greek cross plan, emphasizing symmetry and the massive dome.

  • Carlo Maderno: Transformed the plan into a Latin cross (Baroque style) and designed the basilica's façade.

  • Gian Lorenzo Bernini: Supervised other artists and focused extensively on the interior decoration.

Pope Paul V (Borghese) and the Laton Cross Plan

• Papacy: Paul V (Borghese) reigned from $1605$ to $1621$.

• Architectural Shifts: His primary architect was Carlo Maderno (the nephew of Domenico Fontana).

• The Final Layout: Under Paul V, the structural shape was ultimately decided to be a Latin cross rather than a Greek cross.

• The Façade: Maderno designed the prominent façade, which carries the inscription: "IN HONOREM PRINCIPIS APOST PAVLVS V BVRGHESIVS ROMANVS PONT MAX AN MDCXII PONT VII".

Gian Lorenzo Bernini’s Contributions

• Patronage: In $1626$, a young Bernini received the patronage of Pope Urban VIII (Barberini).

• Career Span: Bernini worked on the embellishment and decoration of the Basilica for $50$ years.

• Succession: He was officially appointed as the successor to Carlo Maderno in $1629$.

• Major Works within St. Peter’s:

  • The Baldachin (Baldacchino): A massive bronze canopy over the main altar. The bronze used for this structure was famously taken from the Pantheon.

  • The Throne of Peter (Cathedra Petri): An ornate reliquary located in the apse.

  • The Statue of Saint Longinus: Housed in one of the piers supporting the dome.

  • Piers of the Dome: Bernini designed the plan for the niches and loggias located within the piers.

  • The Tomb of Pope Alexander VII (Chigi): A late Baroque masterpiece.

  • The Chapel of the Sacrament: One of the highly decorated internal chapels.

  • St. Peter’s Square (Piazza San Pietro): The massive elliptical space framed by colonnades.

  • Scala Regia: The official monumental entrance to the Papal Palace, designed with a tapering perspective to appear longer than it is.

Archaeology and the Tomb of St. Peter

• Historical Levels: Archaeological excavations have revealed multiple layers of history beneath the current structure:

  • Level 1: Pre-Constantinian structures (Old Roman burial ground and catacombs).

  • Level 2: Constantinian structures (The foundations of the 4th-century basilica).

  • Level 3: Structures from the 16th century (The current basilica).

• The Graffiti Wall: Archaeological efforts discovered a wall covered in ancient graffiti near the central tomb site.

• "Petros eni": A crucial inscription found at the site, which translates to "Peter is here."

• Skeletal Remains:

  • Discovery: Human skeletal remains were found in a repository within the graffiti wall.

  • Storage: These remains were kept in a wooden box, which was overlooked for approximately ten years before being recovered by chance.

  • Identification: Forensic analysis identified fragments from several parts of the body as belonging to St. Peter:

    • Fragment from the skull (cranium).

    • Fragment from the left shoulder (clavicle).

    • Fragments from the left forearm (ulna).

    • Fragment from the right arm (humerus).

    • Fragments of the right and left thighs (femur).