When Michael II died , his realm was divided, with Nikephoros receiving the metropolitan territories of Epirus proper and John taking over the Epirote domains in Thessaly and Central Greece. According to Gregoras, his realm extended from
Mount Olympus in the north to
Mount Parnassus in the south, with the
Achelous River serving as his border with Epirus proper; his capital was at Neopatras. Michael VIII seized the opportunity of Michael's death for a rapprochement with the two brothers. He gave Nikephoros his niece
Anna in marriage, and arranged a marriage between his nephew
Andronikos Tarchaneiotes and a daughter of John, who in addition received the high title of
sebastokratōr. Nevertheless, John fiercely guarded his independence, and was prepared to ally himself with Latin powers hostile to Palaiologos, namely
Charles of Anjou and the
Duchy of Athens. He soon emerged as "the more dangerous and the more actively hostile" of the minor Greek rulers against Michael VIII. As
Donald Nicol writes, he "was a man of great resource and ambition, and was clearly in touch with the Emperor's opponents in Constantinople. His stronghold of Neopatras was uncomfortably close to the Latin-occupied parts of Greece, particularly the Duchy of Athens and Thebes with which he was in alliance; and it was easier for troublemakers and refugees from [Constantinople] to make their escape to Thessaly than to Epirus". This is well illustrated by the affair of John's son-in-law, Andronikos Tarchaneiotes: angered at the Emperor's preference for his younger brother Michael, he provoked a
Tatar raid into
Thrace, and in the confusion sought refuge at John's court. The first documented contacts between John and Michael VIII's arch-enemy, Charles of Anjou, also date to the same time (April 1273). A commercial treaty was concluded, allowing the export of
silk from Thessaly to
Apulia and the import of horses from Italy, but it is clear that these contacts were also the first steps for John joining the coalition being prepared by Charles against Constantinople and its ruler. Michael VIII sought to counter the threat of a new crusade, led by Charles of Anjou and aiming at the restoration of the
Latin Empire, by negotiating a union of the
Roman Catholic and
Eastern Orthodox churches. The Union of the Churches was concluded at the
Council of Lyons in 1274, at which the Emperor's representatives were forced to recognize
Papal primacy. This decision aroused passionate opposition from the Byzantine people, the Orthodox clergy, and even within the imperial family itself. Michael VIII's sister
Eulogia, and her daughter Anna, wife of John's half-brother Nikephoros, were among the chief leaders of the anti-Unionists. Nikephoros, John, and even the
Emperor of Trebizond,
John II Megas Komnenos, soon joined the anti-Unionist cause and gave support to the anti-Unionists fleeing Constantinople. Michael VIII asked
Pope Gregory X to
excommunicate John Doukas, but the Pope, who was probably uncertain of the Byzantine emperor's true loyalties, refused. Michael VIII would continue to press Gregory's successors,
Innocent V and
Nicholas III, for the same, as well as for a dissolution of John's alliance with Charles, but without success. In 1275, Michael VIII sent an army under his brother John Palaiologos and
Alexios Kaballarios against John. The Byzantines surprised John at Neopatras and laid siege to his fortress, before he could react. John saved himself by sneaking through enemy lines disguised as a lowly groom seeking a stray horse, and made his way to the
Duke of Athens,
John I de la Roche. Having secured 300 horsemen from him, he returned to Neopatras and
scattered the Byzantine army. In exchange for this aid, however, John gave his daughter to de la Roche's son,
William de la Roche, with the towns of
Zetounion,
Gardiki,
Gravia, and
Siderokastron as her dowry. In April 1277,
papal legates arrived at Constantinople and forced Michael VIII, his son and heir
Andronikos, and the Patriarch
John XI Bekkos, to publicly reaffirm their allegiance to the Union at a synod in the
Palace of Blachernae. John once more rejected Michael VIII's overtures for an acceptance of the Union, and on 1 May 1277, convoked a synod of his own at Neopatras which
anathematized the Emperor, the Patriarch, and the Pope as heretics. In response, a synod was convoked at the
Hagia Sophia on 16 July where both Nikephoros and John were anathematized in return. John convoked another synod at Neopatras in December 1277, where an anti-Unionist council of eight
bishops, a few
abbots, and one hundred
monks, again anathematized Emperor, Patriarch and Pope. Only two bishops, those of
Trikala and
Neopatras, refused, and were punished. Michael VIII then launched another invasion, led by the
pinkernēs Manuel Raoul, the
prōtostratōr Andronikos Palaiologos, and others. Instead of confronting the
sebastokratōr, however, they fraternized with him and gave every sign of their own opposition to the Union. Michael VIII relieved and imprisoned them and appointed new commanders, the
John Synadenos and the
megas konostaulos Michael Kaballarios. The latter were lured by John Doukas into an ambush and suffered a crushing defeat at
Pharsalos. Michael VIII died on 11 December 1282, while preparing to invade Thessaly again. With the threat of an Angevin invasion having subsided following the
Sicilian Vespers, his successor,
Andronikos II Palaiologos (r. 1282–1328), was quick to repudiated the hated Union of the Churches. As a result, ecclesiastical ties between Thessaly, Epirus, and Constantinople were restored. Nikephoros of Epirus, a weak ruler dominated by his wife, and uneasy with his half-brother's ambitions—there are hints in the sources that John coveted Epirus, and that he had launched an attack on Ioannina—now drifted into the Byzantine orbit. Anna visited her cousin Andronikos II at Constantinople, and a plot was hatched against John: in 1283 or 1284 Nikephoros and Anna invited John's son Michael to Epirus to marry their daughter, and become the heir to their state. When Michael took the bait, he was arrested and shipped off to Constantinople, where he died in prison. Andronikos launched an invasion of Thessaly, but his troops were annihilated by
malaria. In the next year (1284 or 1285), John took his revenge for his half-brother's treason by invading Epirus and raiding the environs of Arta. Following this punitive expedition, relations between Thessaly and Epirus settled down to an uneasy peace. For many years, modern historians, following the 19th-century scholar
Karl Hopf, erroneously held that John Doukas died in 1296. It has since been established that he died in or shortly before March 1289. He was buried in the monastery of
Porta Panagia, which he had founded in 1283. His tomb lies in the south side of the
katholikon, and a
fresco above his tomb shows him "as a monk being presented by an angel to the enthroned Virgin". After his death, his widow was compelled to recognize the suzerainty of Andronikos II Palaiologos to safeguard the position of her underage sons
Constantine and
Theodore. Just as when John himself had done so in the past, however, this suzerainty was purely nominal. ==Family==