Thessaloniki, the second heart of the Byzantine Empire
Located at the head of the Thermaic Gulf, near the mouth of the Vardar River and the Via Egnatia, Thessaloniki gained significant importance in late Antiquity. After the loss of much of the empire to the Arabs, Thessaloniki’s prominence grew, becoming the second most important Byzantine city after Constantinople. It remained a major economic and cultural center during the later Byzantine period and was fiercely contested by various powers and during the Byzantine civil wars. Despite enduring long Ottoman rule and the devastating fire of 1917, Thessaloniki preserves numerous Byzantine monuments, making it essential for the study and understanding of Byzantine art and history.
The historical significance of Thessaloniki in Byzantine times.
Late antiquity and early Byzantine times.
From the 3rd century, its position became strategically crucial for countering barbarian invasions across the Danube and managing East-West confrontations. Emperor Galerius established his residence in the city, spurring extensive building activity. In 298–299, a mint opened there, gradually replacing the one in Serdica. For a time, Thessaloniki served as Constantine I’s headquarters, but he later demoted the city, using it as a place of exile for Licinius.
In 390, Emperor Theodosios I ordered the massacre of thousands in the city’s hippodrome as punishment for the murder of a barbarian general. Germanic invasions in the 4th and 5th centuries bypassed Thessaloniki, but Prokopios described it in the 6th century as “easily assailable by barbarians.” In 479, fearing an imminent Ostrogothic attack, the citizens seized the city keys from the distrusted eparch and entrusted them to the bishop. From the late 6th century, the city endured repeated Slavic sieges. According to legend, only the miraculous intervention of St. Demetrios saved it. While Thessaloniki remained under Byzantine control, its hinterland fell to Slavic settlers.
The bishopric of Thessaloniki, traditionally established by Saint Paul, was initially under the jurisdiction of Rome. However, from the second half of the 6th century, Constantinople strengthened its grip on Thessaloniki. Around 733, the now archbishopric of Thessaloniki was transferred to the jurisdiction of the Patriarchate of Constantinople. It was soon demoted to the 16th rank within the patriarchate’s hierarchy, with only five suffragans. Nonetheless, the city remained an important religious seat throughout Byzantine history and the center of the cult of Saint Demetrios.
Thessaloniki in the middle Byzantine times.
From the mid-5th century, Thessaloniki was the capital of the prefecture of Illyricum. After the loss of Egypt, North Africa, and the Near East, Thessaloniki emerged as the second most important Byzantine city after Constantinople. Between the 7th and 9th centuries, it was administered by an eparch, and later by a doux.
The economic life of Thessaloniki in the 7th and 8th centuries remains poorly documented. Some construction and church decorations continued, and a salt pan operated. However, the city’s mint ceased production, resuming only in the 9th century. In the late 9th century, efforts to redirect Bulgarian trade from Constantinople to Thessaloniki failed due to Bulgarian mistrust. Although Symeon of Bulgaria’s invasions of Macedonia spared the city, the pirate Leo of Tripoli sacked Thessaloniki in 904.
Following peace with Bulgaria and its conquest by Basil II, Thessaloniki became a major center for economic and cultural exchange in the southern Balkans. By the 12th century, as noted in the Timarion, it attracted merchants from Scythia, Iberia, Lusitania, and the Transalpine “Celtic” lands. Italian merchants began establishing colonies there. In 1185, the Normans besieged and captured Thessaloniki, committing atrocities that shocked contemporaries.
In the late Byzantine times, a disputed cultural and economic center.
Although the Byzantines reclaimed the city, the Fourth Crusade’s sack of Constantinople in 1204 made Boniface of Montferrat king of Thessaloniki, with territory in Macedonia and western Thrace, and interests extending to the Peloponnese. After the Battle of Adrianople in 1205, Kalojan besieged Thessaloniki. The city withstood the attack, but in December 1224, Theodore Komnenos Doukas, Despot of Epirus, captured it. Thessaloniki remained part of the Despotate until John III Vatatzes annexed it in 1246.
In 1308, the Catalan Grand Company unsuccessfully besieged Thessaloniki. From 1320, it became a focal point of conflict between Andronikos II and Andronikos III. In 1334, the city walls repelled Stefan Uroš IV Dušan’s forces, though the Serbs attacked again in 1341. During the 1340s, Thessaloniki came under the control of the Zealots, an intense episode often interpreted as a revolt against aristocratic power.
The Ottomans launched their first assault on Thessaloniki in autumn 1383, capturing it in April 1387. It briefly returned to Byzantine hands but fell again to Bayezid I on April 12, 1394. After the Battle of Ankara in 1402, the Byzantines regained Thessaloniki, establishing it as a despotate. However, in 1423, Despot Andronikos surrendered the city to Venice, hoping the Republic could prevent its fall to the Ottomans. Despite Venetian efforts, Murad II captured Thessaloniki on March 29, 1430, after a brief siege.
The Byzantine monuments of Thessaloniki.
Thessaloniki preserves many Byzantine monuments. The richness of its heritage, especially its religious buildings that still retain parts of their original decoration, has justified the inclusion of its Byzantine legacy on the UNESCO World Heritage List.
The fortifications.
One of the most impressive features of Thessaloniki is the northern section of its land walls. After the Hellenistic walls had fallen into disrepair, the city was refortified in the mid-3rd century in response to barbarian invasions. This was followed by a major reconstruction that established the layout of the fortifications for the entire Byzantine era. Scholars have debated the exact timing of this construction, but it likely occurred in the mid-5th century. In 512, repairs were made to the west wall. After that, there is no evidence of restoration until the third quarter of the 12th century. During this time, the walls repeatedly protected the city from attacks by Slavs and Bulgars. The poor condition of the fortifications may help explain the city’s capture by Leo of Tripoli in 904.
John Kaminiates described the land walls as strong and high, while the sea wall was completely useless for defense. Writing in the 12th century, Eustathios of Thessaloniki emphasized that the sea walls were built “non-professionally” and were allowed to fall into disrepair by the governor. Repairs are attested in the 12th century and again under Manuel II, probably between 1369 and 1373.
The fortifications can be divided into two sections: the city walls and the citadel. The walls of the lower city form a rough rectangle, wider in the east than in the west. The sea wall to the south has almost completely disappeared, except for the so-called White Tower, which may have been constructed during Venetian rule. The east wall rises nearly straight from the sea, while the west wall follows an undulating course northward and eastward. The citadel occupies a height in the northeastern corner of the city.
From the fortifications, over 20 gateways and 100 towers are preserved, most originally triangular or rectangular in shape. Numerous inscriptions have also survived, including those of the strategos Leo Chitzilakes (ca. 904), Anna of Savoy (1355–1356), and the doux George Apokaukos. Apokaukos served under the despotes Manuel Palaiologos, the future emperor, when he governed Thessaloniki between 1369 and 1373.
Civil architecture and monuments.
Some remains of civil architecture have also been preserved in the city. A large building, identified as a Byzantine palace, has been unearthed in its center. In the northern area, Byzantine baths are still visible.
Churches and monasteries.
Thessaloniki is home to a rich array of churches and monasteries spanning several centuries. Among the earliest are the Church of the Acheiropoietos, the Church of St. Demetrios, and the Church of St. George, all dating from the 5th to the 12th centuries. These churches, along with Hagia Sophia and the Church of the Holy Apostles, are some of the city’s most iconic monuments, reflecting the grandeur of early Byzantine architecture. The 12th century also saw the construction of the Church of Hosios David, which is renowned for its mosaics.
Moving into the 13th century, the Church of St. Nicholas Orphanos and the Church of Panagia ton Chalkeon were built, both showcasing distinct architectural features characteristic of the period. From the late 13th century, the Church of St. Catherine stands out for its unique design and decorative elements.
The 14th century brought several churches that are notable for their lively architecture and impressive frescoes, such as the Church of St. Elijah, the Church of St. Panteleemon, and the Church of the Taxiarchs.
In addition to these churches, Thessaloniki retains several important monasteries, including those of Akapniou, Blatadon, and Nea Mone, which further enrich the city’s religious and architectural heritage.
Sources and further ressources.
The Oxford Dictionary of Byzantium. Edited by Alexander P. Kazhdan, Oxford University Press, 1991.
Paleochristian and Byzantine Monuments of Thessalonika – UNESCO World Heritage Centre
