John III Doukas Laskaris was a Byzantine emperor who ruled from 1221 to 1254. He was a member of the Laskaris family and became the emperor of the Empire of Nicaea, which was established after the fall of Constantinople to the Fourth Crusade in 1204. His reign is noted for efforts to restore the Byzantine Empire and for his military campaigns against the Latin Empire. During his rule, John III focused on strengthening the economy and administration of the empire. He successfully expanded his territory and improved relations with neighboring states. His leadership laid the groundwork for the eventual recapture of Constantinople in 1261, marking a significant moment in Byzantine history.