5. The Palace of Galerius

It is time to be introduced to Galerius, who ruled during what is known as the period of the Roman Tetrarchy and is responsible for some of the most iconic Roman monuments that can be admired today in Thessaloniki. 

Let’s start the story of Galerius from the beginning: In the last quarter of the 3rd century AD, after a period of transition in the Roman Empire, the Emperor Diocletian decided to implement administrative and economic reforms to maintain the stability and continuity of the empire, which had expanded to the point where it was becoming difficult to govern. 

One of these reforms was the Tetrarchy, a model in which the Empire was divided into four administrative units, governed by two Augusti and two Caesars. The title Caesar ranked below Augustus, so it was as if the empire had two "senior emperors" and two "junior emperors". 

During the Tetrarchy  at the end of the 3rd century AD, the Augusti were Diocletian and Maximian and the Caesars were Galerius and Constantius Chlorus. But don’t think that this meant there was division in the empire, as the four rulers worked closely together.

Gaius Galerius Valerius Maximianus (to give him his full name) was a Roman of humble origins. He was born into a farming family in Dacia (close to today’s Sofia, in Bulgaria) and, like his father, initially worked as a shepherd. However, he decided to pursue a military career, and thanks to his abilities and his marriage to the daughter of Emperor Diocletian, he rose through the ranks of the Roman army. The highlight of his career came at the end of the 3rd century when he was appointed Caesar – and later Augustus – of what is now the Balkan peninsula, up to his death in 311 AD.

Following a successful campaign against the Persians, Galerius chose Thessaloniki as his base in 299 AD and immediately set out to transform it into an imperial capital worthy of his status. 

From the first years of the 4th century, he embarked on an ambitious city redevelopment plan that included magnificent buildings and an expansion to the eastern city limits. The result is what we now know as the Galerius Palace Complex which, alongside the Roman Forum, forms the heart of Roman Thessaloniki. 

The central building was the Palace of Galerius, located where Navarinou Square stands today. And to the north of the palace – where Dimitriou Gounari Street is found today – was a ceremonial road with a covered colonnade.

The Arch of Galerius (also known as the Kamara) remains visible today as part of this ceremonial road, which continued beyond the arch and reached the Rotunda, which was also part of the complex and is one of modern Thessaloniki’s most famous landmarks. 

Around these core buildings lay numerous auxiliary structures, creating a wider complex spanning over 150,000 square metres that stretched from the Rotunda to the sea walls. These buildings not only served practical functions and Galerius' personal needs but also symbolised imperial authority and grandeur, reflecting the importance that Galerius attached to Thessaloniki as the centre of his administration.

Of course, reimagining Roman Thessaloniki wouldn’t be complete without mentioning the era's most important trade and military route, the Via Egnatia. 

This was a public road built by the Romans outside Italy, connecting Rome to its eastern territories for commercial and military purposes. The ceremonial road from the Palace of Galerius intersected the Via Egnatia... and it is at this intersection that the Arch of Galerius – or the Kamara – still stands today.

The archaeological site by Navarinou Square showcases Thessaloniki’s Roman heritage in a way that makes it uniquely tangible. Woven into the urban fabric of today’s city, this is what has so far come to light of the centrepiece of the 4th century AD Galerius Palace Complex. 

Like many Roman palaces, it was built around an atrium, an open courtyard surrounded by a Π-shaped peristyle that was decorated with mosaic floors. Beyond Galerius' private quarters and those of his guards, the palace included numerous other buildings serving administrative, religious and social functions. For instance, it featured a Nymphaeum, a space for worship, and a luxurious bath complex for residents.

But the most impressive and best-preserved part of the Palace of Galerius was the Octagon, located in the southwest section. We can still admire it today, an opulent, eight-sided building measuring 30 metres in diameter and 29 metres in height, designed to offer sea views. Part of its floor, which was entirely paved in marble, has been preserved. But the exact function of the Octagon is unclear. It was intended as a throne room or a reception chamber but it is possible that it functioned as a Christian church.

To the east of the palace was a large rectangular hall known as the Basilica, used for receptions and audiences. Between the Basilica and the eastern walls lay the Hippodrome, a vast structure measuring 450 by 95 metres and covering 30,000 square metres, roughly aligned with today’s Hippodromiou Street. As in other Roman cities, Thessaloniki's Hippodrome served as a centre for entertainment and social gatherings, hosting horse races, chariot races and gladiatorial games – popular Roman pastimes.

Lastly, we have the northern section of the palace, at the intersection of Alexandrou Svolou and Dimitriou Gounari streets, featuring an arched hall likely used as a banquet room. 

The complex also included corridors, staircases, and auxiliary spaces connecting the buildings, once richly decorated with mosaic floors, marble panels and frescoes.

The palace likely met its end after sustaining damage from an earthquake in the 8th century. But it isn’t hard to imagine this once-lavish residence of Galerius by touring at least a part of the palace and envisioning Thessaloniki as a vibrant Roman city.