After the recapture of Constantinople by the Byzantine Greeks in 1261, two crowns were added (over each head) representing - according to the most prevalent theory - the newly recaptured capital and the intermediate 'capital' of the empire of Nicaea. The eagle was soon made to 'hold' in its feet symbols of the dual sovereignty (secular and religious) of the Emperor - also represented by its two heads -, such as a sword and a globe with cross. Many modifications followed in flag details, often combined with the cross. During his reign, Emperor Isaac I Comnenus (1057вЂ“1059) modified it as double-headed, influenced by traditions about such a beast in his native Paphlagonia in Asia Minor (in turn reflecting possibly much older local myths). Indeed, the early Byzantine Empire inherited the Roman eagle (extended wings, head facing right) as an imperial symbol. However, there is virtually no doubt that its origin is a blend of Roman and Eastern influences. Greek scholars have tried to make links with ancient symbols: the eagle was a common design representing power in ancient city-states, while there was an implication of a 'dual-eagle' concept in the tale that Zeus left two eagles fly East and West from the ends of the world, eventually meeting in Delphi thus proving it to be the center of the earth. More recent research has justified this view, connecting this symbol only to personal and dynastic emblems of Byzantine Emperors. Yet another theory is that this symbol was only connected with a particular period of Greek history (Byzantine) and a particular form of rule (imperial). One suggested explanation is that, upon independence, an effort was made for political - and international relations - reasons to limit expressions implying efforts to recreate the Byzantine empire. It may seem surprising that one of the most recognizable (other than the cross) and beloved Greek symbols, the double-headed eagle, is not a part of the modern Greek flag or coat of arms (although it is officially used by the Greek Army, by the church of Greece, and was incorporated in the Greek coat of arms between 19).

Flag of the byzantine empire