Significant Historical Events

The person who commissioned the construction of the first basilica was the Roman Emperor Constantine I, the first Roman emperor to embrace Christianity. He planned the church to be built directly over the tomb of Saint Peter, on a hilly and uneven terrain. Construction began around 318–322 AD, and the building was completed in less than forty years. The basilica was erected to honor the noble act of martyrdom of Saint Peter for his faith.

According to historical records, Saint Peter was executed under the orders of Emperor Nero during the Great Fire of Rome in 64 AD. Nero blamed the Christians for the fire, marking the first imperial persecution of Christianity. Saint Peter was sentenced to crucifixion; however, he requested to be crucified upside down, believing himself unworthy to die in the same manner as Jesus Christ. When Emperor Constantine I decided to build a basilica in honor of Saint Peter, he deliberately chose the very site where Saint Peter had been martyred and buried.

In 846, recognizing the significance and wealth of the old basilica, the Saracens, a term commonly used in medieval Europe to refer broadly to Muslim forces, launched an attack and destroyed large portions of the church, including parts of the Tomb of Saint Peter. Over the following one thousand years, the basilica continued to flourish as one of the most important churches in Rome.

Before Pope Julius II ordered the demolition of the old Saint Peter’s Basilica, the structure had stood for nearly 1,200 years. By the 15th century, the building had fallen into serious disrepair, compelling Pope Julius II to commission the construction of a new basilica. Nevertheless, in order to preserve the spirit of the original church, the new design drew inspiration from the early architectural plan. Even today, remnants of the old basilica—such as columns and mosaic artworks can still be found within the present structure.

In the year 800, Charlemagne was crowned Emperor at the basilica.

Specifically, in 800 AD, Charlemagne was crowned Roman Emperor by Pope Leo III at Saint Peter’s Basilica. This event marked the restoration of the imperial title in Western Europe after more than three centuries and signaled the rise of the Carolingian Empire. This empire later came to be known as the Holy Roman Empire, although the term itself was not formally used until the 13th century.

Charlemagne conquered vast territories and expanded his realm, unifying much of Western Europe under his rule. Pope Leo III, in gratitude for Charlemagne’s protection and in an effort to restore papal authority, bestowed the imperial crown upon him in a solemn ceremony. Charlemagne’s coronation held not only political significance but also profound religious meaning, symbolizing the alliance between monarchical power and the Catholic Church.

In 1950, archaeological excavations conducted beneath the main altar of Saint Peter’s Basilica uncovered human remains dating back to the 1st century. These relics are believed to belong to a man approximately 60 years old, and the majority of scholars consider them to be the remains of Saint Peter. In 2013, Pope Francis publicly displayed these relics for the first time during a Mass. The remains are currently preserved with great care beneath the main altar of the basilica.