Theodore Lascaris I - Laskarid Emperors of Nicaea:

First emperor of Nicaea (1208–21), the son-in-law of Byzantine emperor Alexius III. He distinguished himself in the Fourth Crusade (1203–4) and formed a new Byzantine state after Constantinople was taken. In c.1214 he signed a treaty defining the frontiers between the new Greek empire of Nicaea and the now Latin empire of Constantinople. He strengthened his ties to the Latin empire by marrying Maria, daughter of Empress Yolande, and by proposing (1219) that Greek and Latin clergy meet to consider the reunion of the two churches. He also betrothed his daughter, Eudocia, to Robert of Courtenay, Yolande's son and successor as Latin emperor. Theodore was succeeded as emperor of Nicaea by his son-in-law, John III Vatatzes.

The name Laskaris derives from Persian lashkar "army", as do English lascar "sailor" and Arabic al-askari "soldier;

Laskarid Emperors of Nicaea:

1204-1222 : Theodore I Laskaris 1222-1254 : John III Doukas Vatatzes 1254-1258 : Theodore II Laskaris 1258-1261 : John IV Laskaris