Linking the Pantheon in Rome with ancient Mausoleums

The Pantheon in Rome is recognized as the best-preserved Roman construction in the world. This statement, however, brings me back to Alexander and his Mausoleum in Alexandria, as discussed in my earlier blog, Speaking of the Mausoleum of Alexander. 

I explained how Alexander’s tomb inspired later kings and rulers to build their own Mausoleum. The same circular shape was declined in different ways, as described in said blog. However, the Pantheon in Rome used very distinct raw materials for its construction that were not available in the days of the Ptolemies when Alexander’s tomb was erected.  

The surviving Pantheon still makes a statement today, and its cupola resting on top of a circular supporting wall has puzzled architects and archaeologists for centuries. Today’s thorough analysis has shed new light on this monument. 

A temple-like front counting 16 monolith Corinthian columns gives access to the Pantheon proper with a diameter of 43.3 meters. The inscription on the front of the temple portico reading that Agrippa, the right arm of Augustus, built this Pantheon is misleading. Recent research has established that Augustus himself ordered the construction of the earliest Pantheon in 27 BC, which had a slightly wider façade. It faced his Mausoleum less than one kilometer away, built one year earlier, in 28 BC. It is noteworthy to keep in mind that both monuments stood outside the ancient city. 

This first Pantheon, dedicated to all the gods, was destroyed in the fire of Rome in 80 AD. Domitian rebuilt it soon enough, but it was burnt again in 110 AD. By that time, both Augustus and Agrippa were long dead. No reason – yet - to put Agrippa’s name on the façade. 

About ten years later, Hadrian built a new Pantheon on top of the charred remains of the previous versions. His building was made to last, and it did. The circular wall is six meters thick and robust enough to support the copula, 40 meters above the ground. The oculus, the opening at the center of the cupola, has a diameter of 8.70 meters. This opening, together with the rows of alcoves inside this cupola, helps to reduce its enormous weight. 

Examining the thin bricks covering the inside and outside concrete walls of the rotunda, scholars discovered that most were stamped with the name of Emperor Hadrian. The cement inside this 6-meter-thick wall is of a unique mix, using lava dust and fine lava gravel. This mixture was so strong that it was used henceforward all over the Roman Empire for the aqueducts, bridges, and other monumental buildings. As an extra, this cement was also waterproof and fireproof. Looking at the outside walls, one will notice many arches incorporated in its design, and their role was to reinforce the walls even further. 

This close examination of the Pantheon leads to further investigation of Hadrian's many monuments. The first visit goes to the Villa Hadriana in Tivoli, just outside Rome. The construction of this villa, which covered an area larger than Pompeii, probably started around 120 AD. It counted at least one thousand rooms and had an underground parking space for his chariots. A closer inspection revealed that the circular building on the central island, which is said to be the personal quarters of Hadrian, has the same diameter as the Pantheon. Speaking of megalomania! 

It transpires that Hadrian was not much loved by the Romans, although he was widely venerated elsewhere in the Empire. Trying to impose himself, he used Agrippa as a publicity stunt on the front of the Pantheon. In his days, 126 AD, the rotunda functioned as a court building. We’ll remember that Hadrian started the construction of his Mausoleum, the later Castel Sant’Angelo, in 130 BC (see: Speaking of the Mausoleum of Alexander). 

Stepping inside the Pantheon, any modern visitor will stop staring in awe at the oculus above their heads. Inevitably, the rain would fall onto the colorful marble floor. This floor was slightly tilted to drain the water through small apertures in the marble slabs and washed away in underground canals. By sunny weather, on the other hand, the light beam would illuminate the niches that once held statues and highlight parts of the marble floor. Hadrian had his statue in a prominent place inside the Pantheon. On April 24, the anniversary of the foundation of Rome, the sun would cover Emperor Hadrian with its godly rays. 

In 609 AD, the Pantheon was converted into a Christian Church dedicated to the Virgin Mary and all the Martyr Saints. This saved the precious building for posterity. In later centuries, it served as a model for the Basilica of the Vatican, Italy; the Panthéon in Paris, France; the Rotunda of the University of Virginia, USA; and many other public buildings all over the world. 

The Rotunda of Galerius in Thessaloniki

Fitting the same list of circular buildings is the Rotunda of Galerius in Thessaloniki, which is still standing. Emperor Galerius built it in 306 AD as his Mausoleum, although it may have served as a Mausoleum for Constantine the Great, who died in 337. Soon after, it became a Christian Church dedicated to the Archangels. After the Ottoman invasion in 1590, Thessaloniki’s church cathedral became a mosque until they were ousted in 1912. This Rotunda is a recognizable copy of the Pantheon in Rome, although smaller. Its height nearly reaches 30 meters to the top of the dome, and the circle measures 24.5 meters in diameter. The dome, which initially had an oculus, is resting on walls that are 6.3 meters thick and built similarly to its example in Rome. The construction is made of bricks that were covered with marble slabs on the outside. However, the interior walls were decorated with early Byzantine mosaics in the 4th-6th century.

Although we have no hard proof that all these Pantheons and Mausoleums arose in the wake of Alexander’s now-lost tomb in Alexandria, the very idea remains very tempting. It is doubtful that Alexander conceived his tomb at any time, neither when he was in Alexandria nor in Babylon. The city of Alexandria was still under construction when the king died, which was why his body was temporarily placed in a tomb in Memphis. Ptolemy I or his son Philadelphus brought Alexander’s golden sarcophagus to his burial site in Alexandria, approximately between 298 and 274 BC. 

Amazingly, no description at all has survived about its exact location. The same mystery surrounds the king’s second grand burial site after Ptolemy IV Philopator had completed the construction of the imposing new Royal Mausoleum. Alexander’s body was moved sometime during his reign, between 221 and 204 BC, and was placed amidst the remains of other members of the Ptolemy dynasty. This necropolis with the Alexander Mausoleum was located somewhere in the middle of the city. Ancient testimonies remain very vague on the subject, and since most of the initial Alexandria lies four or five meters under the modern metropolis, it will not reappear soon.

In any case, the Mausoleum of Alexander existed from the third century BC till after the reign of Emperor Hadrian, who died in 138 AD. Crowds of people paid tribute to Alexander over the centuries and yet his tomb could not be located!

[Picture 1 from Tiqets.com - Picture 2 from Wikimedia - Picture 3 from Wikipedia - Picture 4 is mine - Picture 5 from Tiqets.com]