The previous post in the Fall of Byzantium series is here.

The Byzantine involvement in the latest war between Venice and Genoa was brief but costly. Everything they had won in the Galata War was lost, and there was a large moral cost to this defeat. John Cantacuzenus was now less popular than ever before.

Around this time his junior colleague, John V Palaeologus, had begun to clamor for his rights. John V had been relegated to the administration of Thessalonica, far from events of real substance in the capital. His supporters told him he was being marginalized, and that he should assert his rights before he lost them. There were still another five years before John V would reach seniority, according to the treaty that ended the civil war. But Cantacuzenus’ popularity being what it was, he could hardly refuse his co-emperor’s demand. The elder John therefore transferred his son Matthew’s appanage in western Thrace to Palaeologus, and moved Matthew to the more important governorship of Adrianople. This was in late 1351.

John was evidently just maneuvering for his next move. No sooner had the peace with Genoa been concluded the following spring, than John V, with the assistance of Serbian troops and Venetian subsidies, launched a surprise attack against Matthew. Palaeologus’ forces drove him from Adrianople and occupied his part of Thrace. The empire was at war with itself again.

The Dilemma

What was Cantacuzenus to do? The empire was exhausted; so was he. The past few years had been a string of misfortunes, and his popularity reflected this. Should he try to negotiate with the young Palaeologus, get him to hold his peace? Or maybe offer to step down and let the legitimate heir take his rightful place?

The younger John’s actions up to date did not indicate that he would be a good ruler. He had already displayed a troubling lack of judgment in the negotiations with Venice—behind the back of the negotiators, he had kept up secret talks in which he was offered a bribe in return for ceding the crucial island of Tenedos, which guarded the mouth of the Dardanelles. Cantacuzenus and the boy’s mother found out and were able to talk him out of such folly, but this episode showed that John Palaeologus was quite evidently willing to sacrifice the interests of the empire for his own.

The decision was clear: Cantacuzenus must fight. That was the only certainty, everything else would be a series of smaller dilemmas. Where to find the troops to fight? What to do with the boy? How to maintain his own standing as emperor?

Déjà Vu

The first question was how to fight the war. Despite John’s efforts in the last few years, the Byzantine army was in a sorry state—manpower was critically short—so he would need to hire mercenaries. The Slavic powers had already contributed troops to Palaeologus’ cause and the Venetians were financing him. This would make Genoa a natural choice, but they still bore John a grudge for his betrayal in the recently-concluded war. Once again, John was forced to turn to the Turks.

John’s old friend Umur Bey had died a few years before. The only real option among the myriad of petty Turkish states in Anatolia was the Ottomans. Since the beginning of the century they had expanded dramatically, to the point where they were now the strongest regional power. Cantacuzenus enjoyed good relations with their sultan Orhan—he even married a daughter to him, a controversial move for a Christian emperor. This was not the same fraternal affection he and Umur had for each other, however. Orhan was more of an opportunist, and would exact a price for whatever support he provided.

The situation now mirrored the last war. Palaeologus was supported by Serbs and Bulgarians while Cantacuzenus had Turks fighting for him. Yet again, those outside powers looked to make whatever few gains they could from the depleted empire. The Turks were the quickest to profit: after helping recapture Adrianople, ten thousand of Orhan’s cavalrymen smashed a Serbian-Bulgarian force, then proceeded to plunder the towns and countryside of Thrace.

This victory brought about a ceasefire, and John V returned to his territory. Later that year, however, when it became clear that Palaeologus’ allies were once again making trouble, Cantacuzenus forced the boy into internal exile on Tenedos, the same island he had tried to sell to the Venetians. The junior emperor soon got restless, slipped his guard, and sailed to Constantinople, where he failed in an attempt to incite the population to insurrection. Cantacuzenus finally realized that John V had to go. Having passed up several opportunities to sideline the legitimate heir in the past, he now declared his co-emperor deposed and raised his own son Matthew to the throne instead.

Shaky Reign

Despite this nominal victory, Cantacuzenus’ popularity was at an all-time low. An emperor’s job is to be the protector of his people, and John had given the Byzantine people no reason to trust in him. His reign had been one calamity after another, without a single resounding victory that could give reason for hope. Even the way in which he deposed Palaeologus—belatedly, after much hesitation—lacked the inspiring ring of confidence; Byzantines had embraced usurper emperors in the past, so long as they had the mettle to live up to the part.

Among the biggest reasons for John’s unpopularity was his relationship to the Muslim Turks. As Emperor of the Romans, he was supposed to be the defender of Christian orthodoxy—he could not be seen as too close to the infidels. John was close friends with Umur of Aydin and had married his own daughter to the Ottoman sultan: some allowance might be made for the straits of circumstance, but he had gone too far. He had also taxed churches and monasteries—an expedient acceptable only in the most desperate times—and had used funds sent by the Grand Prince of Moscow for the repair of the Hagia Sophia to instead pay for Muslim mercenaries. Turkish troops caused enormous devastation during the previous civil war, and rogue bands of them did not stop raiding into Europe in the meantime. It was as if Cantacuzenus had invited a plague into the empire, yet even now he persisted in his error.

Then in 1354, a devastating earthquake struck the southern coast of Thrace, leveling the city of Gallipoli. Most of the houses were destroyed, the fortifications were damaged, and the majority of the population fled. Orhan’s son Suleiman promptly seized the defenseless city, claiming that the earthquake was a sign from Allah that he had given the city to the Turks. When John complained of this to Orhan, the father blew him off; for all John’s debasing alliance and marriage of his own daughter to Orhan, he could not even get satisfaction. Gallipoli, which guarded the Dardanelles, was the Turks’ first possession in Europe—its conquest was an omen of what was to come. What the Turks interpreted as divine favor, the Byzantines could only see as God’s judgment.

End of the War

As Cantacuzenus’ popularity continued to slide, he attempted some sort of reconciliation with his former colleague at Tenedos. The latter absolutely refused to see him, leaving the emperor alone in charge of a diminished and ungovernable empire. Things persisted in this uncomfortable state for several months until, one night late in 1354, John V left Tenedos and slipped back into Constantinople. News quickly reached Cantacuzenus that his rival was back in the capital and that the population had risen against him. With an angry mob surrounding the palace, John at last admitted defeat and welcomed Palaeologus as emperor in his own right.

A few days later, John Cantacuzenus abdicated the throne and announced he was entering a monastery. Whether John V forced him to do this or it was his own idea, he had long dreamed of giving up the cares of rule. Matthew Cantacuzenus would hold out for a few years more before himself abdicating and accepting a fief in the Peloponnese, but his father was done. In his new life as a monk, John would write the history of his age, an apology for his reign. In our next and final post on John Cantacuzenus, we will look at his legacy and what it tells us about the Byzantine Empire of his day.