Greek: Δικεφαλος αετος
Origins: Hittite civilization
Symbolized: The Byzatine Empire
The double-headed eagle was a symbol used by the Byzantine Empire and the Holy Roman Empire that has been adopted by several Eastern European nations as their national symbol to this day. The two heads of the eagle represent the dual sovereignty of the Empire (secular and religious), with the head on the left symbolizing Rome and the head on the right symbolizing Constantinople. The symbol of the eagle was in use for centuries before, by the Armenians and the Seljuk Sultanate of Rum before it was officially adopted by the Byzantium’s.
Constantinople, the centre of the Byzantine Empire, was the successor of Rome who continued the use of the old imperial single-headed eagle. In Rome, it symbolized imperial authority and the bronze aquilas and vexilloids (similar to flags) were used whenever the emperor was present. The single-headed eagle turned double when Isaac I Komnenos, sometime from 1057-1059, modified it after being influenced from local traditions from his native Paphlagonia in Asia Minor.
From Byzantium, the two-headed eagle spread to Russia after Ivan III’s marriage to Zoe Palaiologina (a niece of Constantine XI, the last emperor of Byzantine). Ivan felt that Russia was the true heir of the Byzantine empire and started adopting the double-headed eagle. It would later be incorporated as an important motif of the imperial families of Russia (the house of Romanov), Austria-Hungary (the House of Habsburg) and the royal family of Montenegro (the House of Petrovic).
It was also used in the Coat of Arms of the Bulgarian Tsar Ivan Alexander in the 14th century and the Serbian Namanjic dynasty as they too claimed the imperial throne of Constantinople after its fall. George Kastrioti also adopted the double-headed eagle in his flag for the Albanians struggle against the Ottoman Empire. They continue to use it to this day as well as many other nations coat of arms, most notably Germany. In Greece, the double-headed eagle is used as the symbol of the Greek Orthodox Church, whose Patriarch still resides in Constantinople. It is also used by the Hellenic Army as their coat of arms.