The Byzantine Successor States, 1204-1261

The Fourth Crusade left the Byzantine world in utter confusion. Since the empire had never been a Greek national state and violent successions were nothing new, at first many provincials failed to see that what had happened was a foreign conquest, and not a somewhat irregular revolution. The Crusaders promptly chose an emperor who was to assume control over the Byzantine church, bureaucracy, and provinces as the successor of Alexius IV Although the better-informed Byzantines and Venetians realized that the old empire was gone, not even they knew quite what was going to take its place.

In March 1204, before the Crusaders and Venetians made their final assault, they had agreed to let a college of six Crusaders and six Venetians choose a new emperor. The emperor elected was to receive a quarter of both Constantinople and the empire as his domain. The forces of the Crusaders and the Venetians would each receive half of the remainder to hold 25 fiefs in vassalage to the emperor. If a Crusader was elected emperor, as everyone assumed would happen, a Venetian was to be patriarch of Constantinople. After taking the city, but apparently before electing an emperor, the Crusaders and Venetians divided the land among themselves. In broad outline, the partition put the imperial domain in Asia Minor and some of Thrace, the crusader fiefs in Greece, and the Venetian fiefs in the islands, some ports, and Epirus.

In May the electors did choose a Crusader emperor, but not Marquis Boniface of Montferrat, who had led the Crusade and expected to be elected. Boniface had already moved into the Great Palace, attracted some Byzantine supporters, and arranged to marry Isaac II’s widow Margaret-Maria. He had earlier family connections with both the Angeli and the Comneni, and was a man of energy and ability. But the Venetians wanted an emperor who would be easier to control, and joined with some French and German Crusaders to outvote Boniface’s Italian followers. They selected the thirty-one-year-old Count Baldwin of Flanders, who was duly crowned.


At first Baldwin, whom Byzantines called the Latin emperor, held only Constantinople and its immediate hinterland. The rest of the empire was subject partly to its bewildered Byzantine governors, and partly to a bewildering crew of rebels and deposed emperors. Alexius V reigned at Tzurulum in eastern Thrace. The previously deposed Alexius III was at Mosynopolis, from which he controlled western Thrace and the region of Thessalonica. Kaloyan of Bulgaria ruled to the north of the two Alexiuses. The rebel magnate Leo Sgurus held the parts of Greece around Nauplia, Corinth, and Thebes. Crete was apparently held by the men of Boniface of Montferrat, whom Alexius IV seems to have granted it in pronoia during his brief reign.

Rhodes was under another Byzantine magnate, Leo Gabalas. Attalia had been seized by the Italian condottiere Aldobrandini. Three more magnates held the Meander valley: Sabas Asidenus around Priene, the old rebel Theodore Mangaphas around Philadelphia, and in the east Manuel Maurozomes, who had given refuge to the fugitive sultan Kaykhusraw. Northwestern Anatolia was held by Theodore Lascaris, a son-in-law and nominal partisan of Alexius III. The Pontus had just fallen to David and Alexius Comnenus, grandsons of the emperor Andronicus who had been lynched nineteen years before. Alexius Comnenus now proclaimed himself Byzantine emperor at Trebizond.

The Byzantine resistance therefore included three men who claimed to be emperor, Alexius III, Alexius V, and Alexius of Trebizond. Of these Alexius III seemed the most plausible. He certainly hoped to retake Constantinople, and with his son-in-law Theodore Lascaris he could claim footholds in both the Balkans and Asia Minor. But he had been a disappointing ruler and had fled from the Crusaders early on. Alexius V had fled later, but after accomplishing even less. Alexius of Trebizond, descended from a widely detested usurper, was far away in a peripheral province. Although Kaloyan of Bulgaria also called himself emperor and was thinking of bigger things, few Byzantines thought of him as one of themselves. The rebel magnates had purely local ambitions. Byzantium appeared to be smashed beyond repair.

By the same token, the Latin emperor Baldwin had a hard task to create a Latin empire that would be nearly comparable to the Byzantine one his men had wrecked. The Latins had already ruined their new capital by plundering it and giving much of the booty to Venice. The Venetian doge Enrico Dandolo was not even Baldwin’s vassal, though many other Venetians were. Boniface of Montferrat, disappointed at losing the imperial election to Baldwin, remained suspicious of him, though Boniface was consoled with the promise of a vassal kingdom around Thessalonica, then held by Alexius III. After first welcoming the Latin capture of Constantinople as a means of reuniting the Church, Pope Innocent discovered how brutal the conquest had been, and condemned the sack of the city and the Crusaders’ plundering of Byzantine church property.

Once elected, Baldwin found himself one of many adventurers, and only a little stronger than the others. That summer he attacked his most formidable Byzantine enemies, the deposed emperors Alexius III and Alexius V. Fleeing west, Alexius V very reasonably sought an alliance with Alexius III, whose deposer he had after all deposed. Alexius III accepted the offer and married his daughter Eudocia to Alexius V, then had his new ally blinded. This stupid act threw away the best chance fro an early and effective Byzantine resistance to the Latins. As Baldwin marched to Mosynopolis, Alexius III retreated before him.

But the Crusaders could be as pigheaded as the Byzantines. The Latins emperor insisted on marching to Thessalonica, ignoring the protests of Boniface, whose kingdom it was supposed to be. Boniface retaliated by attacking Baldwin’s men around Adrianople. This dangerous dispute was hastily arbitrated by the crusader barons and the Venetians. Boniface agreed to leave Baldwin’s domain and to sell Venice his holdings in Create for a thousand marks, while Baldwin let Boniface occupy Thessalonica and help the Crusaders claim their fiefs in Greece. Toward the end of the summer, the confused Thessalonians received Boniface as their king.

Among the Byzantines accompanying Boniface was Michael Ducas, the cousin of Alexius III who had rebelled against him in 1200. In early autumn, however, Michael left for Epirus to answer an appeal from a local governor related to him. Arriving to find his relative dead, Michael stayed at Arta to organize Byzantine resistance in Epirus. Mountainous Epirus, though not rich, was easy to defend against the Latins, and Michael, though a bastard, had his connection with the Angelus dynasty in his favor, and a driving ambition at a time when many others were uncertain what to do next.

Meanwhile Alexius III retreated to Greece, where he joined forces with the rebel magnate Leo Sgurus. Sgurus married Alexius’s daughter Eudocia, undeterred by Alexius’s treatment of her previous husband Alexius V Alexius V was now dead, having been captured after his blinding and killed by the emperor Baldwin. Before the Byzantine alliance between the deposed emperor and the rebel magnate had taken definite shape, King Boniface of Thessalonica advanced into Greece. He captured Alexius III and drove Sgurus into the Peloponnesus, besieging him in the Acrocorinth, Corinth’s almost impregnable upper town. Thus the two former Byzantine emperors, Alexius III and Alexius V, were put out of contention.

While Boniface expanded his vassal Kingdom of Thessalonica, the emperor Baldwin took over his designated holdings in Thrace and prepared to claim his Anatolian domains from Theodore Lascaris. Theodore, apparently still professing loyalty to his father-in-law Alexius III, had organized an army in the northwest. But Theodore had plenty of Byzantine rivals to his rear. The rebel magnates remained active in the south, while the self-proclaimed emperor Alexius of Trebizond had sent his brother David with an army that captured coastal Paphlagonia. Against this divided Byzantine opposition, the Latins crossed the Hellespont and defeated Lascaris near Poemanenum, south of the Sea of Marmara. They went on to besiege Lascaris’s city of Prusa.

The Latins were apparently carrying everything before them. Michael Ducas of Epirus submitted to Pope Innocent to protect his fledgling state. Kaloyan of Bulgaria also made an agreement with the pope, accepting the authority of the papacy in return for a royal crown from Rome. As a nominal member of the western church, Kaloyan then offered an alliance to the Latin emperor Baldwin. But Baldwin refused, annoyed that Kaloyan had been taking border territory in Thrace.

The Crusaders seemed to need no allies. In early 1205 Baldwin’s brother Henry led reinforcements into Asia Minor, captured Adramyttium, and defeated the magnate Theodore Mangaphas. In the Balkans King Boniface of Thessalonica conquered Euboea, central Greece, and most of the eastern Peloponnesus, where he continued besieging Sgurus in the Acrocorinth. The western Peloponnesus fell to some Crusaders recently arrived from Syria, who defeated an army apparently brought from Epirus by Michael Ducas.

Rebuffed by the emperor Baldwin, Kaloyan of Bulgaria incited the Byzantines in Latin Thrace to revolt. They expelled the Latins from Adrianople and several other towns. Baldwin, with whatever troops his brother had not taken to Asia Minor, marched on Adrianople and besieged it. In April Kaloyan arrived with his army and attacked the Latin emperor. The Bulgarians routed the overconfident and outnumbered Latins, killing many of them and capturing Baldwin himself. The aged doge Dandolo died soon afterward. After so much rapid success, suddenly the Latin Empire seemed on the verge of collapse.

Baldwin’s brother Henry hurried back to Constantinople to assume the regency of the Latin Empire and call for help from the West. He had to abandon practically all his conquests in Anatolia to Theodore Lascaris. Kaloyan, who already held most of Thrace, turned on the Kingdom of Thessalonica and sacked Serres before King Boniface could arrive from the Peloponnesus. But Kaloyan made the mistake of mistreating and fighting his Byzantine allies, and the Latins profited by recapturing some of Thrace. Since Kaloyan failed to exploit his victory, the main beneficiary of the Latin rout was Theodore Lascaris. The Latins had already broken the power of one of his rivals, Theodore Mangaphas, whom Lascaris soon took prisoner. When Alexius of Trebizond’s brother David sent an army against Theodore, Lascaris defeated it and captured its commander. Probably after this victory, Theodore proclaimed himself Byzantine emperor at Nicaea.

Now that the new emperor of Nicaea had defeated the forces of Alexius of Trebizond, while Alexius III was Boniface’s captive, Theodore had as good a claim as anyone to the imperial title. Aged about thirty-one, with no less ability than his rivals and more vision, Theodore had already built up a functioning successor state in northwestern Anatolia from next to nothing. Later in 1205 the Nicene emperor defeated his two competitors to the south, Sabas Asidenus and Manuel Maurozomes. By early 1206 Theodore made peace with Maurozomes, who kept only the border forts of Chonae and Laodicea as a vassal of the recently restored sultan Kaykhusraw. Theodore tried to secure his claim as the leading Byzantine pretender by inviting the exiled patriarch of Constantinople John to leave the rebel-held part of Thrace for Nicaea. But the patriarch would not desert his embattled countrymen, and in any case died in spring 1206.

The same spring Kaloyan raided Thrace with a ferocity that drove the Byzantine rebels into the arms of the Latin regent Henry. The rebels surrendered Adrianople to Theodore Branas, a Byzantine general in Henry’s service, and allowed Henry and his men to reoccupy most of Thrace. Having learned that his brother Baldwin had died in Bulgarian captivity, Henry had himself crowned Latin emperor. Although the Latin Empire he inherited was gravely weakened, he was a much more gifted leader than his brother and set about regaining what had been lost.

Henry tried to restrain Theodore Lascaris of Nicaea by allying with David Comnenus, the last Byzantine rival bordering on Theodore’s territory. The Nicene emperor was marching on David’s city of Heraclea Pontica when the Latins attacked him from the rear, and he had to turn back to chase them off. In the winter the Latins invaded Theodore’s lands again, capturing Nicomedia and Cyzicus from him. He retaliated by persuading Kaloyan to attack Latin Thrace. In spring 1207 Henry had to withdraw troops from Anatolia to rescue Adrianople from the Bulgarians. To obtain a badly needed truce from Theodore, the Latin emperor agreed to return Nicomedia and Cyzicus to him.

By this time all the surviving combatants were becoming exhausted. The Latins seemed to have Kaloyan at bay, until the Bulgarians ambushed and killed Boniface of Thessalonica in late summer. Kaloyan was besieging Thessalonica when he too suddenly died in the early autumn. Since both Boniface and Kaloyan left only underage sons, a group of rebellious barons took over Thessalonica, and Kaloyan’s nephew Boril usurped the Bulgarian throne. Both Bulgaria and Thessalonica were incapacitated.

By early 1208 the major players eliminated some minor ones from the game and made matters a little less chaotic. Leo Sgurus, cornered on the Acrocorinth by the Latins, committed suicide by riding his horse off a cliff. The sultan Kaykhusraw took Attalia from the freebooter Aldobrandini. Venice and its vassals finished conquering most of the islands except Crete, which had been seized by the Genoese. Theodore Lascaris chose a patriarch, nominally of Constantinople but resident at Nicaea, who crowned him emperor, nominally of the Byzantine Empire but at Nicaea for the present.

That summer the Latin emperor Henry crushed a raid by Boril of Bulgaria, secured Thrace, and took Philippopolis. Henry then marched against the rebel barons of Thessalonica. In the first part of 1209 he suppressed their rebellion by a combination of diplomacy and warfare, installed his brother Eustace at Thessalonica as regent for Boniface’s infant son, and received the homage of the Latin vassals throughout Greece. To avoid trouble with the resurgent Latins, Michael Ducas of Epirus married his daughter to Eustace and made a formal submission to Henry.

After several years of anarchy, the principal powers within former Byzantine territory had established themselves. Except for Genoese Crete, independent Rhodes, and Turkish Attalia, nearly all the lands that had been Byzantine around 1200 were in the hands of four rulers. The emperor of Nicaea Theodore ruled western Anatolia. The emperor of Trebizond Alexius held the Crimea and the northern Anatolian coast, including Paphlagonia under his brother David. Michael Ducas, content to do without a title, ruled Epirus. The remainder of Greece and almost all of Thrace were subject to the Latin emperor Henry and his vassals, who had subdued the Bulgarians and made the Latin Empire the leading state in the region. Though the three main Byzantine successes held about half of what had been Byzantine territory, they remained rivals.

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