Marcian

Upon becoming Eastern Roman Emperor, Marcian reversed the policy of paying tribute to Attila the Hun. He declared that he had gold for his friends but iron for his enemies. This defiance marked a shift in Eastern policy and contributed to Attila's decision to invade the West.

Marcian convened the Council of Chalcedon, the fourth ecumenical council. The council condemned the Monophysite heresy and defined the Chalcedonian Creed, which affirmed the two natures of Christ. This decision had lasting theological and political consequences for the Christian world.

Marcian implemented fiscal reforms that stabilized the Eastern Roman Empire's economy. He abolished the tax on the city of Constantinople and reduced state expenditures, leaving a substantial treasury surplus upon his death.