Double-headed Eagle - Byzantine Empire

Byzantine Empire

Constantinople was the successor of Rome, and the Byzantine Greeks continued the use of the old imperial "single-headed" eagle motif. Although the roots of the transformation to double-headed are almost certainly connected with old depictions in Asia Minor, the details of its adoption are uncertain. It was, however, already in use by the 10th century.

The Ancients used no flags in the modern sense. The Romans used various signa, such as the bronze aquilas (adopted as the legions' symbol by Marius) and vexilloids, and, if the emperor was present, pikes or banners with the emperor's portrait. With the adoption of Christianity as state religion during the later Empire, the Chi-Rho and the cross became more and more used in military standards, such as the labarum. The Roman single-headed eagle however continued to be used as a symbol of imperial authority.

According to the most prevalent theory, the single-headed eagle was modified to double-headed by emperor Isaac I Komnenos (1057–1059) being influenced from local traditions about such a (mythical) beast (the haga) in his native Paphlagonia in Asia Minor. Local legends talked about this giant eagle with two heads that could easily hold a bull in its claws; the haga was seen as a representation of power, and people would often "call" it for protection. Isaac Komnenos, deeply influenced by these beliefs, had already used it as a family emblem.