Theodore II Lascaris

Theodore II Doukas Laskaris Θεόδωρος Β΄ Δούκας Λάσκαρις
Portrait of Theodore II from a 15th-century manuscript
Emperor of Nicaea
Reign	1254–1258
Predecessor	John III Doukas Vatatzes
Successor	John IV Laskaris
Born	c. 1222 Nicaea, modern Iznik, Turkey
Died	18 August 1258(1258-08-18) Magnesia, modern Turkey
Spouse	Elena of Bulgaria
Issue	John IV Doukas Laskaris Irene Doukaina Laskarina Maria Doukaina Laskarina Eudoxia Laskarina
Father	John III Doukas Vatatzes
Mother	Irene Lascarina

Theodore II Doukas Laskaris or Ducas Lascaris (Greek: Θεόδωρος Β΄ Δούκας Λάσκαρις, Theodōros II Doukas Laskaris) (1221/1222 – August 18, 1258) was Emperor of Nicaea from 1254 to 1258.

Theodore II Doukas Laskaris was the only son of Emperor John III Doukas Vatatzes and Eirene Laskarina, the daughter of Emperor Theodore I Laskaris and Anna Angelina, a daughter of Emperor Alexios III Angelos and Euphrosyne Doukaina Kamaterina. Theodore was born in late 1221 or early 1222, reportedly on the very day his father ascended the throne.

Theodore II received a scholarly education by George Akropolites and Nicephorus Blemmydes the latter who would become a tutor to him, and remained devoted to science and art throughout his life. In contrast with earlier practice, Theodore II was not crowned co-emperor with his father, though he assisted in the government since c. 1241. On the death of John III on November 4, 1254, Theodore II was acclaimed emperor by the army and the court, but was crowned only after the appointment of a new patriarch, Arsenios Autoreianos, in 1255.

The succession of Theodore was exploited by the Bulgarians, who invaded Thrace under the leadership of the young and inexperienced Michael Asen I of Bulgaria in 1255. In spite of his own scholarly predisposition, Theodore immediately marched against the Bulgarians and inflicted a crushing defeat on them. During his second expedition in 1256, he managed to conclude a favorable peace with Bulgaria, which may have plunged the latter into a crisis of leadership. Theodore followed up his victory against Bulgaria by expanding his control in the west, where he annexed Durazzo and Servia, effectively outflanking his rivals in Epirus.