When did the second Bulgarian empire reach its greatest power?

The Second Bulgarian Empire reached its greatest power during the reign of Tsar Ivan Asen II, who ruled from 1218 to 1241.123

During this period, Bulgaria became the leading power in the Balkans, exerting control over Albania, Epirus, Macedonia, and Western Thrace. Key milestones of this era included:23

• Military Success: Following his victory over the despot of Epirus in 1230, Ivan Asen II significantly expanded the empire's territory.1
• Cultural and Religious Growth: The first Bulgarian coinage was introduced, and in 1235, the head of the Bulgarian church was elevated to the title of patriarch.23
• Administrative Stability: As a capable administrator, Ivan Asen II restored law and order and effectively managed the boyars.1

After his death, the empire struggled to maintain this influence due to internal instability, pressure from the nobility, and external threats such as Mongol invasions.23