For the entirety of its two millennia, the Pantheon has been used as a place of worship. It was first built as a temple to the Roman Gods around 126 AD, and became a church after the Empire converted to Christianity in the 7th century - its internal niches now contain fine Catholic artwork including frescoes and Byzantine icons, and a magnificent high altar was added in the 17th century. The building’s consecration protected it from the terrible damage suffered by much of Rome’s ancient architecture during the early medieval period.
To this day, the Pantheon hosts religious masses and weddings. It is also the resting place for many eminent Romans, including the artist Raphael and the first king of Italy, Victor Emmanuel II.
A monumental feat
From an architectural perspective, the Pantheon remains one of the great wonders of the world. The sixteen vast granite Corinthian columns of its portico - which each weigh 60 tons - were quarried in Egypt, dragged 100km on wooden sledges to the Nile, floated by barge down the river, crossed the Mediterranean Sea in ships to Ostia, then were transferred back onto barges to travel up the Tiber to Rome - before being rolled another 700 metres to the Pantheon. Quite a journey!
Its rotunda is no less impressive, crowned by the world's largest unreinforced concrete dome, whose height is exactly equal to the rotunda’s diameter - a 43.3m sphere fits perfectly inside. It is only relatively recently that architects have come to understand how the dome can support itself, let alone withstand the many earthquakes over its long history.
The dome’s 4,535 ton construction is ingenious. It reduces in thickness from 6.4m at the base to just 1.2m at the crown, further lightened by internal coffering; its aggregate consists of heavy travertine at the base, then lighter terracotta tiles, then even lighter porous tufa and pumice at the top. At the very apex, where the dome would be at its most vulnerable to collapse, there is no concrete at all: the oculus, a 9m circular aperture, lightens the load as well as allowing in a beam of sunlight. The polychrome marble floor features concealed bronze drainage holes to handle water ingress during storms.
Michelangelo himself was greatly moved by his first sight of the Pantheon, declaring it to be the work of angels; he was inspired to design the dome of St. Peter's Basilica
, by which time the Pantheon was already almost 1,500 years old. It also inspired Brunelleschi’s stunning 15th century dome for Santa Maria del Fiore
in Florence. The Pantheon remains today as stunning testament to the Roman Empire’s majesty, and one of the most influential and impressive buildings of all time.