Byzantine Civil War of 1321–1357
The Byzantine Civil War of 1321–1357 was a significant internal conflict within the Byzantine Empire that arose from political strife among the ruling elite. The war began when Emperor Andronicus II Palaeologus disinherited his grandson Andronicus III, leading to a power struggle that saw both factions vying for control of the empire. Initially, the conflict included scattered skirmishes in Thrace, but it escalated as major cities, like Thessalonica, shifted allegiances.
The civil war unfolded in two main phases, with Andronicus III ultimately gaining control after the abdication of his grandfather in 1328. Following Andronicus III's death in 1341, the conflict reignited as political factions formed around his widow, Anna of Savoy, and the ambitious John VI Cantacuzenus. The war saw shifting alliances, including appeals to external powers like the Ottoman Turks, which aided Cantacuzenus in his military campaigns.
As the war progressed, local urban populations often aligned against the aristocracy, leading to violence and instability in key cities such as Constantinople and Thessalonica. The conflict concluded in 1357 with the deposition of Cantacuzenus's son and the reinstatement of John V Palaeologus, marking a pivotal moment that allowed the Ottoman Turks to solidify their presence in Europe. This tumultuous period not only reshaped the Byzantine political landscape but also set the stage for the expansion of Ottoman influence in the Balkans.
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Byzantine Civil War of 1321–1357
At issue: Who would be emperor
Date: 1321–1357
Location: Thrace around Constantinople
Combatants: Byzantine emperors and usurpers
Principal commanders: Andronicus II (1260–1332) vs. Andronicus III (1296?-1341); then John V Palaeologus (1332–1391) vs. John VI Cantacuzenus (1292?-1383)
Principal battles: Siege of Didymotichus, Siege of Thessalonica, Hebrus
Result: The Byzantine Empire was torn apart and the Ottoman Turks entered Europe
Background
The large landowners who were the Byzantine ruling classes of the later empire had long shown themselves willing to fight each other at the expense of a common effort against external enemies. In the early fourteenth century, these nobles were much resented by the poor in the cities. At the same time, Byzantium was menaced by the Serbian Empire in the Balkans and the Turks of Asia Minor.
In 1320, the old emperor Andronicus II Palaeologus cut his grandson Andronicus out of the succession because he had killed his brother by mistake in a love intrigue. The younger Andronicus collected supporters, including his friend John VI Cantacuzenus, and fled to Adrianople. In spring, 1321, he proclaimed himself Emperor Andronicus III.
Action
In the first phase of the civil war, scattered fighting took place between the supporters of Andronicus II and Andronicus III in Thrace in 1321–1322, but when Thessalonica, the second city of the empire, declared for the younger Andronicus, the elder one made peace and divided the empire with him. The younger Andronicus resumed the fight in 1327; in late May, 1328, the people of Constantinople let him into the city with 800 followers. He forced his grandfather to abdicate, and the latter died in 1332.
Andronicus III reigned with John VI Cantacuzenus as his grand domestic (chief general). When he died in 1341, his widow, Anna of Savoy, at first accepted John VI Cantacuzenus as main regent for the nine-year-old John V Palaeologus, but then, while he was on campaign, deposed him as grand domestic and raised the Grand Duke Alexius Apocaucos. John VI Cantacuzenus proclaimed himself emperor at Didymotichus, and the civil war resumed.
In this second phase, both sides said they supported the boy emperor John V, but the urban commons decided that Anna and Alexius Apocaucos were his legitimate regents and John VI Cantacuzenus was a usurper from the hated military aristocracy. They therefore sacked the houses of his family and friends in Constantinople and drove governors who supported John VI Cantacuzenus out of Adrianople in 1341 and Thessalonica in 1342. John VI Cantacuzenus’s wife Irene held Didymotichus (1343) with Bulgar help until he relieved it with 6,000 Turkish troops from his personal friend the emir of Aydin. He advanced in Thrace in 1344, captured Adrianople in early 1345, and advanced to the Black Sea coast with help from the Ottoman emir Orhan.
Alexis Apocaucos was murdered in mid-1345, and his son was then massacred with the other nobles in Thessalonica (1345–1350), whose commons formed a popular regime that held out against John VI Cantacuzenus until 1350. Anna tried to use Turkish troops against John VI Cantacuzenus in 1346, but he had real ties with their chiefs, and they defected to him. In February, 1347, John VI Cantacuzenus’s partisans in Constantinople let him and 1,000 supporters into the city. Anna gave up without a fight, and he became the senior emperor John VI.
John V, at last old enough to act for himself, restarted the war in 1352 by attacking Cantacuzenus’s son Matthew in Adrianople and collecting Serbian, Bulgarian, and Venetian allies. Cantacuzenus relieved Adrianople and sent for 10,000 Ottoman auxiliaries. These forces fought a pitched battle on the Hebrus or Maritsa River (late 1352); John VI Cantacuzenus’s Turks won, and he deposed John V in 1353 and had Matthew crowned coemperor in February, 1354. However, in March, his Ottoman auxiliaries took advantage of an earthquake to occupy Gallipoli and fortify it as the first permanent Turkish fortress in Europe. John V came to Constantinople in November, and the angry commons rose in his favor. John VI Cantacuzenus reinstated him and then resigned to become a monk. His son Matthew refused to yield to John V and marched on him with 5,000 Turks in 1356. He was captured and resigned the imperial title at the end of 1357.
Aftermath
John V was sole emperor for thirty-four more years. As a monk, John IV Cantacuzenus wrote the history of the civil war period. The Ottoman Turks, having gotten a foothold in Europe as a result of this war, advanced into the Balkans.
Bibliography
Nicol, Donald M. “a.d. 1354: Annus fatalis for the Byzantine Empire.” In Geschichte und Kultur der Palaiologenzeit. Vienna: Verlag der Oesterreichischen Akademie der Wissenschaften, 1996.
‗‗‗‗‗‗‗. The Last Centuries of Byzantium, 1261–1453. 2d ed. Cambridge, England: Cambridge University Press, 1993.
‗‗‗‗‗‗‗. The Reluctant Emperor: A Biography of John Cantacuzene, Byzantine Emperor and Monk, c. 1295–1383. Cambridge, England: Cambridge University Press, 1996.