Michael VIII Palaiologos in the context of "Theodore II Laskaris"

The Palaiologan army refers to the military forces of the Byzantine Empire under the rule of the Palaiologos dynasty, from the late 13th century to its final collapse in the mid-15th century. The army was a direct continuation of the forces of the Empire of Nicaea, which itself was a fractured component of the formidable Komnenian army of the 12th century. Under the first Palaiologan emperor, Michael VIII, the army's role took an increasingly offensive role whilst the naval forces of the empire, weakened since the days of Andronikos I Komnenos, were boosted to include thousands of skilled sailors and some 80 ships. Due to the lack of land to support the army, the empire required the use of large numbers of mercenaries.

After Andronikos II took to the throne in 1282, the army fell apart and the Byzantines suffered regular defeats at the hands of their eastern opponents, although they would continue to enjoy success against the Latin territories in Greece. By c. 1350 the Empire's inefficient fiscal organization and incompetent central government made raising troops and the supplies to maintain them a near-impossible task, and the Empire came to rely upon troops provided by Serbs, Bulgarians, Venetians, Latins, Genoese and Turks to fight the civil wars that lasted for the greater part of the 14th century, with the latter foe being the most successful in establishing a foothold in Thrace. By the time the civil war had ended, the Turks had cut off Constantinople, the capital of the Byzantine Empire, from the surrounding land and in 1453 the last decisive battle was fought by the Palaiologan army when the capital was stormed and sacked, falling on 29 May.

The Byzantine Empire was ruled by emperors of the Palaiologos dynasty in the period between 1261 and 1453, from the restoration of Byzantine rule to Constantinople by the usurper Michael VIII Palaiologos following its recapture from the Latin Empire, founded after the Fourth Crusade (1204), up to the Fall of Constantinople to the Ottoman Empire. Together with the preceding Nicaean Empire and the contemporary Frankokratia, this period is known as the late Byzantine Empire.

From the start, the regime faced numerous problems. The Turks of Asia Minor had begun conducting raids and expanding into Byzantine territory in Asia Minor by 1263, just two years after the enthronement of the first Palaiologos emperor Michael VIII. Anatolia, which had formed the very heart of the shrinking empire, was systematically lost to numerous Turkic ghazis, whose raids evolved into conquering expeditions inspired by Islamic zeal, the prospect of economic gain, and the desire to seek refuge from the Mongols after the disastrous Battle of Köse Dağ in 1243. The Palaiologoi were engaged on several fronts, often continually, while the empire's supply of food and manpower dwindled. In this period, the Byzantine Empire found itself continually at war, both civil and interstate, with most interstate conflicts being with other Christian empires. Most commonly, these comprised the Second Bulgarian Empire, the Serbian Empire, the remnants of the Latin Empire and even the Knights Hospitaller.

The House of Laskaris (Greek: Λάσκαρις (Láskaris), later Λάσκαρης; feminine form Laskarina; Greek: Λασκαρίνα), Latinized as Lascaris, was a Byzantine Greek noble family which rose to prominence during the late Byzantine period. The members of the family formed the ruling dynasty of the Empire of Nicaea, a Byzantine rump state that existed from the 1204 sack of Constantinople by the Fourth Crusade until the restoration of the Empire under the Palaeologan dynasty in 1261.

Upon the sack of the Byzantine capital by the Crusaders, Alexios V Doukas was overthrown and the Latin Empire was established in most of his former lands. Byzantine nobility would flee the Latin territories and establish the three independent Greek states that rivaled the Crusaders. After a successful resistance in Asia Minor, Theodore I Laskaris founded the Empire of Nicaea and laid claims to the Byzantine throne, along with the Angelos family of Epirus and the Komnenoi of Trebizond. The Byzantine Greek population of Asia Minor sought refuge to Theodore's empire, which gradually acquired control over much of western Anatolia. The empire was further strengthened after the military victories of Theodore's successor, John III Vatatzes. John's son, Theodore II Laskaris, maintained the empire's strength until the throne was passed to his underage son, John IV Laskaris. In 1259 John fell victim to an aristocratic conspiracy which managed to establish Michael Palaiologos as his regent and co-emperor.

Irene Komnene Palaiologina (Greek: Εἰρήνη Κομνηνή Παλαιολογίνα, romanized: Eirēnē Komnēne Palaiologína; c. 1218–1284), after c. 1261 known by her monastic name as Eulogia (Εὐλογία), was an elder sister of the Byzantine emperor Michael VIII Palaiologos. Originally close to the emperor, her opposition to the Union of the Churches in 1273 led to their estrangement, and even to intrigues by Irene against Michael involving foreign rulers. As a result, she was imprisoned for the remainder of his reign. After Michael's death, she encouraged Andronikos II Palaiologos to repudiate the Union.

Stefan Uroš II Milutin (Serbian Cyrillic: Стефан Урош II Милутин, romanized: Stefan Uroš II Milutin; c. 1253 – 29 October 1321), known posthumously as "the Holy King" (Свети краљ), was the King of Serbia between 1282–1321, a member of the Nemanjić dynasty. He was one of the most powerful rulers of Serbia in the Middle Ages and one of the most prominent European monarchs of his time. Milutin is credited with strongly resisting the efforts of Byzantine Emperor Michael VIII Palaiologos to impose Roman Catholicism on the Balkans after the Union of Lyons in 1274. During his reign, Serbian economic power grew rapidly, mostly due to the development of mining. He founded Novo Brdo, which became an internationally important silver mining site. As most of the Nemanjić monarchs, he was proclaimed a saint by the Serbian Orthodox Church with a feast day on October 30.

Alexios Komnenos Strategopoulos (Greek: Ἀλέξιος Κομνηνὸς Στρατηγόπουλος) was a Byzantine aristocrat and general who rose to the rank of megas domestikos and Caesar. Distantly related to the Komnenian dynasty, he appears in the sources already at an advanced age in the early 1250s, leading armies for the Empire of Nicaea against Epirus. After falling out of favour and being imprisoned by Theodore II Laskaris, Strategopoulos sided with the aristocrats around Michael VIII Palaiologos, and supported him in his rise to the throne after Theodore II's death in 1258. He participated in the Pelagonia campaign in 1259, going on to capture Epirus, but his successes were undone in the next year and he was captured by the Epirotes. Released after a few months, he led the unexpected reconquest of Constantinople from the Latin Empire in July 1261, restoring the Byzantine Empire. He was captured again by the Epirotes in the next year and spent several years in captivity in Italy, before being released. He retired from public affairs and died in the early 1270s.

The Battle of Pelagonia or Battle of Kastoria took place in early summer or autumn 1259, between the Empire of Nicaea and an anti-Nicaean alliance comprising Despotate of Epirus, Kingdom of Sicily and the Principality of Achaea. It was a decisive event in the history of the Eastern Mediterranean, ensuring the eventual reconquest of Constantinople and the end of the Latin Empire in 1261.

The rising power of Nicaea in the southern Balkans, and the ambitions of its ruler, Michael VIII Palaiologos, to recover Constantinople, led the formation of a coalition between the Epirote Greeks, under Michael II Komnenos Doukas, and the chief Latin rulers of the time, the Prince of Achaea, William of Villehardouin, and Manfred of Sicily. The details of the battle, including its precise date and location, are disputed as the primary sources give contradictory information; modern scholars usually place it either in July or in September, somewhere in the plain of Pelagonia or near Kastoria. It appears that the barely concealed rivalries between the Epirote Greeks and their Latin allies came to the fore in the lead-up to the battle, possibly fanned by Palaiologos' agents. As a result, the Epirotes abandoned the Latins on the eve of the battle, while Michael II's bastard son John Doukas defected to the Nicaean camp. The Latins were then set upon by the Nicaeans and routed, while many nobles, including Villehardouin, were taken captive.