Who was Emperor John III Doukas Vatatzes and what was his legacy?

John III Doukas Vatatzes was a Byzantine Emperor who ruled from 1221 to 1254. He was the founder of the Vatatzes dynasty, which ruled the Byzantine Empire until its final collapse in 1453. Vatatzes is known for his military campaigns against the Bulgarians and the Seljuk Turks, as well as his efforts to strengthen the Byzantine economy and administration.

Under Vatatzes, the Byzantine Empire experienced a period of relative stability and prosperity, which was in contrast to the chaos and decline that had characterized the preceding decades. He pursued a policy of territorial expansion, conquering much of Bulgaria and parts of Asia Minor. Vatatzes was also a patron of the arts and learning, and he sponsored the construction of several important buildings and churches.

Perhaps Vatatzes' greatest legacy was his role in preserving and revitalizing the Byzantine Empire during a time of crisis. He reorganized the army and navy, reformed the tax system, and established a network of provincial governors to oversee the administration of the empire. His reign was marked by a resurgence of Byzantine power and culture, and he set the stage for the later Byzantine Renaissance.