After crusaders from the Fourth Crusade sacked Constantinople in 1204—instead of attacking and subduing Egypt as the original plan was meant to be—the vast Byzantine Empire splintered into four main, distinct entities, comprising a Latin successor state in the Balkans and Constantinople itself, and three Byzantine Greek rump states. One of these in north-eastern Anatolia became the small Empire of Trebizond, which I looked at in a recent blog (08-May-2024), ‘Byzantine-Lite: The Empire of Trebizond under the Komnenos Dynasty’.

The largest and most powerful of the Greek successor states to emerge was Nicaea (then the name of a city-state in north-western Anatolia). Styling itself under the cognomen Empire of Nicaea, the dominant Laskaris family of nobles, proclaimed Theodore (I) Lakaris emperor (basileus) in 1205. The Laskarii staked a claim on the Byzantine throne as well but had plenty of competition, the other two Greek Byzantine successor states, Trebizond and (the Despotate of) Epirus, both advanced claims to be the rightful heirs to the Byzantine crown.

Proceeding by conquest, alliance and intermarriage: While Theodore I and his successors within the Lakaris dynasty were eyeing off Byzantium, the Nicene Empire had plenty of more immediate challenges to face. The territorial boundaries of the empire was surrounded by hostile states, so it had to deal constantly with multiple conflicts and crisis points. Ongoing wars were waged against the Latin Empire𝕬 (Henry of Flanders, Robert of Courtenay) to the north; against the Seljuk Turks of Iconium (Asia Minor); and against its rival successor states, Trebizond and Epirus𝕭. Aside from waging war Theodore deflected some of the threats to Nicaea by the stratagem of alliances and arranged royal marriages.

Less Roman, more Hellenistic: Theodore’s successor as emperor John III Doukas Vatatzes (his son-in-law) continued the strategy, allying with Bulgaria against the Latins and to help neutralise any threats from Epirus𝕮. John failed in a combined Nicaean-Bulgarian siege of Constantinople in 1235 but his reign did achieve military victories and diplomacy which resulted in an enlargement of Nicaea’s imperial territories…eg, Battle of Poemanenum, 1224, John decisively defeated the Latin army, giving Nicaea a foothold on the Balkans littoral; military campaigning against Epirus led to new Nicene gains in Macedonia and Thrace (Thessalonica fell to John in 1246). John’s successful rule also benefitted from his domestic policy, the economy was reformed, agriculture boomed, taxes were reduced and prosperity in Nicaea thrived. Emperor Theodore II, a man of letters, succeeeded John III, marking a cultural renaissance for the empire – Hellenistic learning flourished with Nicaea forging a more distinctly overt Greek identity, throwing off the shadow of its Roman past. At the same time Theodore undertook a military restructuring, the creation of a formidable army of native Greek troops, ending the state’s reliance on foreign mercenaries [‘The Rise of the Empire of Nicaea: How the Byzantines Reclaimed the Throne’, Timeless Treasure, (video, You Tube) Nov. 2023].

Palaiologos’ palace coup: Theodore II’s reign unfortunately was too brief, he died in 1258 after only four years at the helm, with the throne falling to his eight-year-old son, John IV, creating a situation ripe for instability and opportunism. The power vacuum was quickly filled by the grand constable (megas konostaulos) Michael Palaiologos who launched a coup, making himself co-emperor with John IV. Within a short period Michael had deposed the infant John (and had him blinded). Taking the throne as sole emperor (basileus), Michael VIII Palaiologos’ dynastic line continued to rule the empire right up to the Ottoman takeover of Constantinople in 1453. Meantime, Michael consolidated his position and that of Nicaea by defeating the alliance of William of Villehardouin, Prince of Achaea and Michael II Komnenos Doukas of Epirus at the Battle of Pelagonia in 1259.

Capturing Constantinople by accident: Pelagonia elevated Michael’s prestige at home, however with the stigma of the “emperor-usurper” still figuring prominently in many Nicaean minds, for genuine legitimacy Michael needed to secure the ultimate goal, the prize of Constantinople [‘Michael VIII Palaiologos’, Wikipedia, http://en.m.wikipedia.org]. First attempts at conquest in 1260 saw Michael personally leading a failed siege attempted on the city. While Michael was doing a deal with the Republic of Genoa to secure naval support for a new assault on the Latin capital, the unexpected happened. Nicaean general, Alexios Strategopolous and a small force were on a reconnaissance mission which took them close to the city of Constantinople, when it stumbled on a virtually unguarded city/citadel (most of the Latin garrison and the naval fleet were away conducting a raid on the Nicene island of Daphnousia). Alexios seized the opportunity and his force surreptitiously found its way inside the fortified walls where it easily overcame feeble resistance. Baldwin II the Latin emperor, panicked and fled the city, leaving the Nicaeans in complete control of Constantinople.

A hollow prize: Michael VIII by a stroke of good fortune had regained Byzantium for Nicaea, but the city and the empire was a shell of its former glory. Constantinople was in a very impoverished and diminished state, ravaged by war, most of its treasure either destroyed or shipped off to Western Europe (much of it ended up in Venice). Michael did what he could to fortify and strengthen the restored empire including a massive building project, but Constantinople as a trading port declined and Byzantium would never again hold the military and economic sway it commanded before the 1204 sacking by the Crusaders. After Charles I of Anjou triumphed over Manfred, king of Sicily (Battle of Benevento, 1266), Michael’s foreign policy became preoccupied with the rivalry with Charles. This proved a catastrophic blunder, long-term, as Michael withdrew troops from their posts in Asia Minor to bolster his army in confronting the Latins in the Aegean littoral, thus weakening his Anatolian defences against the burgeoning threat posed by the Seljuks to his east.

Byzantine post-Michael VIII, the inevitable decline and fall: After Emperor Michael’s death in 1282, his dynastic successors managed merely to squander the restored empire’s “remaining resources in several bloody civil wars” [‘The Accidental Reconquest of Constantinople’, Krystian Gajdzis, Medium, 28–Aug-2022, www.medium.com]. The cost of looking inward was ill-fated neglect of the growing menace of the tribe of Osman and their descendants’ piecemeal capture of Byzantine cities across northern Anatolia, taking them inexorably closer and closer to Constantinople, something succeeding Byzantine emperors were increasingly powerless to prevent [Roger Crowley, 1453: The Holy War for Constantinople and the Clash of Islam and the West, (2005)].

𝕬 the Latins were regularly bankrolled by the affluent Republic of Venice

𝕭 Nicaea got some respite from Seljuk border raids with the appearance of the all-conquering Mongol horde in Anatolia, forcing the Sultanate of Rum to focus its energies on repelling the Mongol advance

𝕮 John continued the practice, marrying off his son (Theodore) to a Bulgarian princess