Angelos

Aspron trachy depicting the Virgin Mary (left) and Isaac II Angelos (right), first ruler of the imperial Angelid dynasty, crowned by saint Michael the Archangel.

Constantine's third son Andronikos Doukas Angelos, was the progenitor of the imperial Angelos dynasty.[10] The Angeloi came into conflict with Emperor Andronikos I Komnenos who had initiated a series of anti-aristocratic policies. In a 1185 coup d'etat, Andronikos' son Isaac II Angelos gained popular support and deposed Andronikos I Komnenos proclaiming himself Byzantine Emperor. The new emperor did not manage to regulate the weaknesses that he inherited, including the abuses in central and provincial administration.[11] Isaac II failed to crush the revolt of the Bulgarians and Walachians and in 1187 he was forced to recognize the Bulgarian empire. Despite those military defeats, Isaac succeeded in retrieving imperial fortunes in the Balkans, after Branas' victory against the Normans at the Battle of Demetritzes in 1185 and the victory against Stephan Nemanja of Serbia in 1190.[12] During Isaac's reign, attempts to usurp imperial power by Byzantine nobles, previously uncommon in the Byzantine history of the 12th century, became a common occurence preventing the empire's complete recovery.[13]

In 1195 Isaac II was deposed by his brother Alexios III Angelos, whose coup and misuse of power accelarated the decline of the empire's stregth. His reign was marked by abuses in provincial administration and an increasing autonomy of regional magnates who would even defy the emperor's authority.[13] In 1201 Isaac's son, Alexius Iv Angelos, made his way to the west, where he succeeded in bringing about the diversion of the Fourth Crusade to Constantinople in order to restore his father, Isaac II, to power.[12][2] On 1 August 1203, the blinded Isaac II was crowned co-emperor, after eight years of imprisonment, along with his son Alexios IV, who held the true power during their reign. After his deposition by the Fourth Crusade, Alexios III fled Constantinople with the goal of collecting support and restoring his reign, but was eventually captured in Nicaea where he died in a monastery in 1211.[14] Despite their initial synergy, the inability of the Angeloi to deal with the Crusaders' demands caused friction between the Crusaders and the co-emperors, who in January 1204 were deposed by Alexios V Doukas and killed shortly after.[15] With their former supporters now dead, the Crusaders had no support in Constantinople, while the anti-Latin sentiment of the citizens was reinforced.[2] Following the brief reign and failed negotiations by Alexios V, the Crusaders sacked Constantinople and established the Latin Empire officially terminating the Byzantine rule for nearly half a century.

Map of the Despotate of Epirus, one the three Byzantine ramp states that emerged in 1205 and laid claim to the Byzantine throne, ruled by the Komnenodoukas branch of the Angelos dynasty.

The Angelos line was continued by the descendants of Constantine's eldest son, the sebastokrator John Doukas.[16] Like John, most of his descendants eschewed the surname "Angelos" and used either "Doukas" or "Komnenos Doukas", after which they are known in modern scholarship as the "Komnenodoukai" (Κομνηνοδούκαι).

After the fall of Constantinople and the establishment of the Latin Empire in 1204, John Doukas' illegitimate son, Michael I Komnenos Doukas, founded the Despotate of Epirus in 1205 choosing the city of Arta as its capital.[17] Initially a vassal and an ally of the Latins, Michael I went on to expand his territories in north-eastern Greece until his death in 1215, when he was succeeded by his half-brother Theodore Komnenos Doukas.[17] In 1224, Theodore captured the Kingdom of Thessalonica from the crusaders and proclaimed himself as the legitimate Byzantine emperor (basileus) in his holdings. Epirus appeared as a serious contender for the Byzantine throne, but Theodore was defeated and captured by John II Asen at the Battle of Klokotnitsa in 1230 and his empire quickly declined following the loses in Macedonia and Thrace.[17] During Theodore's captivity, his brother Manuel ruled over Thessalonica, succeeded by Theodore's sons John and Demetrios. In 1242 the Nicaean emperor John III Doukas Vatatzes compelled John to abandon the imperial title (keeping only the title of despotes),[18] and by 1246 Thessalonica was captured by Nicaea, marking the end of the Angelid rule in much of northern Greece.[19]

In 1230, Theodore's nephew Michael II, son of Michael I, established himself as ruler of Epirus and Thessaly and was partially successful in recapturing holdings lost to Nicaea.[17] After the death of Michael II in 1268, Epirus was ruled by his legitimate son Nikephoros I, while Thessaly – now separated from Epirus – was given to his illegitimate son John I Doukas.[18] The Komnenodoukas family lost both Epirus and Thessaly in 1318; Nicholas Orsini, Count of Cephalonia, murdered Nikephoros' son Thomas I, ending the rule of the family in Epirus, while in Thessaly John I Doukas was succeeded by his son Constantine, followed by John II, who ruled from 1302/03 until his death in 1318.[18] In the same year, the south of Thessaly was seized by the Catalan Grand Company and annexed to the Duchy of Athens, while the north passed to a series of autonomous magnates.