Laskaris in the context of "Nicaean Empire"

The Empire of Nicaea (Greek: Βασιλεία Ῥωμαίων), also known as the Nicene Empire, was the largest of the three Byzantine Greek rump states founded by the aristocracy of the Byzantine Empire that fled when Constantinople was occupied by Western European and Venetian armed forces during the Fourth Crusade, a military event known as the Sack of Constantinople. Like the other Byzantine rump states that formed due to the 1204 fracturing of the empire, such as the Empire of Trebizond and the Despotate of Epirus, it was a continuation of the eastern half of the Roman Empire that survived well into the Middle Ages. A fourth state, known in historiography as the Latin Empire, was established by an army of Crusaders and the Republic of Venice after the capture of Constantinople and the surrounding environs.

Founded by the Laskaris family, it lasted from 1204 to 1261, when the Nicenes restored the Byzantine Empire after they recaptured Constantinople. Thus, the Nicene Empire is seen as a direct continuation of the Byzantine Empire, as it fully assumed the traditional titles and government of the Byzantines in 1205.

The Trapezuntine emperors were the rulers of the Empire of Trebizond, one of the successor states of the Byzantine Empire founded after the Fourth Crusade in 1204, until its fall to the Ottoman Empire in 1461. All but two of the Trapezuntine rulers belonged to the Komnenos dynasty, which had previously ruled the Byzantine Empire from 1081 to 1185. They initially claimed to represent the legitimate line of Roman emperors, in opposition to the Latin Empire in Constantinople, the Laskaris dynasty of the Nicene Empire, and the Komnenos Doukas family of Epirus and Thessalonica. To emphasize their dynastic claim, Trapezuntine emperors from the late 13th century onwards styled themselves as Megas Komnenos (Μέγας Κομνηνός, lit. 'Grand Komnenos').

Out of the Byzantine claimants that emerged in 1204 and thereafter, the Trapezuntine emperors, despite their illustrious descent, had perhaps the worst position. Not only were they far away from Constantinople in a peripheral province of the empire, but the reputation of the Komnenoi had been severely damaged by the detested last emperor of the dynasty, Andronikos I Komnenos (r. 1183–1185), grandfather of the first Trapezuntine emperor Alexios I (r. 1204–1222). Though they continued to claim to be the legitimate rulers of the entire former Byzantine Empire for decades thereafter, conflict with the Nicene Empire and the Sultanate of Rum in the early 13th century reduced the power of the Trapezuntine emperors. After the fall of Sinope to Sultan Kaykaus I in 1214, the Empire of Trebizond ceased to be a major contender for restoring the Byzantine Empire and became reduced to a small and local power.

The House of Palaiologos (pl. Palaiologoi; Ancient Greek: Παλαιολόγος, pl. Παλαιολόγοι; female version Palaiologina; Ancient Greek: Παλαιολογίνα), also found in English-language literature as Palaeologus or Palaeologue, was a Byzantine Greek noble family that rose to power and produced the last and longest-ruling dynasty in the history of the Roman Empire. Their rule as Byzantine emperors lasted almost two hundred years, from 1259 to the fall of Constantinople in 1453.

The origins of the family are unclear. Their own medieval origin stories ascribed them an ancient and prestigious origin in ancient Roman Italy, descended from some of the Romans that had accompanied Constantine the Great to Constantinople upon its foundation in 330. It is more likely that they originated significantly later in Anatolia since the earliest known member of the family, possibly its founder, Nikephoros Palaiologos, served as a commander there in the second half of the 11th century. Over the course of the 12th century, the Palaiologoi were mostly part of the military aristocracy, not recorded as occupying any administrative political offices, and they frequently intermarried with the then ruling Komnenos family, increasing their prestige. When Constantinople fell to the Fourth Crusade in 1204, the Palaiologoi fled to the Empire of Nicaea, a Byzantine successor state ruled by the Laskaris family, where they continued to play an active role and occupied many offices of high rank.