The double headed eagle can be found on inumerous civilizations and empires.

https://www.youtube.com/watch?v=psZ1UaZ9Bhc

This source claims that it symbolizes Roman and Constatinople representing each head.

The source also claims the eagle came into existence around 30 AD Roman Empire.

What the double sided eagle really represents is that they operate both sides. In linguistic terms they are two faced.

Always play both sides. History is theatre for forced change.