What is byzantine empire flag?

The flag of the Byzantine Empire was a multi-coloured square or rectangular banner. It featured a gold double-headed eagle on a red background, symbolizing the empire's unity between the East and West. The eagle held in its talons a globe representing the world and a sword representing the military power of the empire. The eagle itself symbolized strength, courage, and wisdom. The Byzantine Empire flag was used from the 12th century until the fall of the empire in 1453.