THEODORE LASCARIS (d. 1222), emperor of Nicaea, was born of a noble Byzantine family. He became the son-in-law of the Emperor Alexius III. and distinguished himself during the sieges of Constantinople by the Latins (1203-4). After the capture of the city he gathered a band of fugitives in Bithynia and established himself in the town of Nicaea, which became the chief rallying-point for his countrymen. Relieved of the danger of invasion by a Latin force which had defeated him in 1204 but was recalled to Europe by a Bulgarian invasion, he set to work to form a new Byzantine state in Asia Minor, and in 1206 assumed the title of emperor. During the next years Theodore was beset by enemies on divers sides. He maintained himself stubbornly in defensive campaigns against the Latin emperor Henry, defeated his rival Alexius Comnenus of Trebizond, and carried out a successful counter-attack upon Gayath-ed-din, the sultan of Koniah, who had been instigated to war by the deposed Alexius III. Theodore's crowning victory was gained in 1210, when in a battle near Pisidian Antioch he captured Alexius and wrested the town itself from the Turks. At the end of his reign he ruled over a territory roughly conterminous with the old Roman provinces of Asia and Bithynia. Though there is no proof of higher qualities of statesmanship in him, by his courage and military skill he enabled the Byzantine nation not merely to survive, but ultimately to beat back the Latin invasion.
See E. Gibbon, The Decline and Fall of the Roman Empire, vol. vi., ed. J. B. Bury (London, 1896); G. Finlay, History of Greece, vol. iii. (Oxford, 1877); and A. Meliarakes, 'Itrropla TOU BoaiXitou rijj Nu-dias teal TOU &e<nroT&Tov rrjs 'Hiriipou (Athens, 1898).
Theodore's grandson, THEODORE II. (Lascaris), emperor from 1254 to 1258, is chiefly noticeable for two brilliant campaigns by which he recovered Thrace from the Bulgarians (1255-56). His ill-health and early death prevented his making full use of his ability as a ruler.
See M. J. B. Pappadopoulos, Theodore II. Lascaris, empereur de Nicee (Paris, 1908;.
Note - this article incorporates content from Encyclopaedia Britannica, Eleventh Edition, (1910-1911)