A relief on the west-facade of the Grand Mosque in Divrigi, a former Byzantine city in central Anatolia. Conquered by the turkes in 1071. This picture inspired me to paint the banner below.
I found the following article on the origin of double headed eagles as a heraldic charge . .http://en.wikipedia.org/wiki/Eagle_(heraldry):
"Twin Headed Eagle and the Turks
The Seljuk Turks emigrating from Central Asia occupied Baghdad in 1055 and Tougrul captured Mosul, and upon returning to Baghdad in 1058 was given the title of the '’King of the East and West'’. The Seljuks were even more anxious to have their rule legitimized: seen as aliens they were unpopular with the townsfolk of Persia and Iraq, and Tougrul's investiture by the Caliph in 1058, in a magnificent ceremony during which two crowns were held over his head as symbols of his regal authority over East and West, confirmed that the he now was the Commander of the Faithful. At the time the double-headed eagle became his and the Seljuk state’s coat of arms and flag, one head symbolizing the east and the other one symbolizing the west. As the Seljuk Empire’s insignia, the twin-headed eagle appears in Turkish coins from 11th century and onwards as well as a number of architectural remains scattered in central and east Anatolia. These architechural remains also depict palm trees under bicephalous eagle as the tree of life, symbolizing peace and prosperity.[...]"
Concerning the twin-headed eagle as the emblem of the holy roman empire Wikipedia says:
"From the reign of Frederick Barbarossa in 1155 the eagle became a symbol of the Holy Roman Empire in its one-headed state. The eagle was clearly derived from the Roman eagle and continues to be important in the heraldry of those areas once within the Holy Roman Empire. Within Germany the placement of one’s arms in front of an eagle was indicative of princely rank under the Holy Roman Empire. The first mention of a double-headed eagle in the West dates from 1250 in a roll of arms of Matthew Paris for Emperor Frederick II."
And last but not least a comment on the byzantine bicephalous eagle http://en.wikipedia.org/wiki/Eagle_(heraldry):
The double-headed Seljuk Eagle became the symbol of the Emperor Michael VIII Palaiologos. Palaiologos recaptured Constantinople from the Crusaders in 1261 and adopted the double-headed eagle as his symbol of the dynasty's interests in both Asia and Europe. It represented looking towards the East (Asia Minor, traditional power center of the Byzantine-government in exile after the IVth Crusade) and the West (newly reconquered land in Europe) centered on Constantinople. The Byzantine double-headed eagle has been seen in late 13th century, certainly pre-dating the development of the same in western heraldry. In Russia it was Ivan III of Russia who first assumed the two-headed eagle, when, in 1472, he married Sophia, daughter of Thomas Palæologus, and niece of Constantine XI, the last Emperor of Byzantium. The two heads symbolised the Eastern or Byzantine Empire and the Western or Roman Empire."
"From the reign of Frederick Barbarossa in 1155 the eagle became a symbol of the Holy Roman Empire in its one-headed state. The eagle was clearly derived from the Roman eagle and continues to be important in the heraldry of those areas once within the Holy Roman Empire. Within Germany the placement of one’s arms in front of an eagle was indicative of princely rank under the Holy Roman Empire. The first mention of a double-headed eagle in the West dates from 1250 in a roll of arms of Matthew Paris for Emperor Frederick II."
And last but not least a comment on the byzantine bicephalous eagle http://en.wikipedia.org/wiki/Eagle_(heraldry):
The double-headed Seljuk Eagle became the symbol of the Emperor Michael VIII Palaiologos. Palaiologos recaptured Constantinople from the Crusaders in 1261 and adopted the double-headed eagle as his symbol of the dynasty's interests in both Asia and Europe. It represented looking towards the East (Asia Minor, traditional power center of the Byzantine-government in exile after the IVth Crusade) and the West (newly reconquered land in Europe) centered on Constantinople. The Byzantine double-headed eagle has been seen in late 13th century, certainly pre-dating the development of the same in western heraldry. In Russia it was Ivan III of Russia who first assumed the two-headed eagle, when, in 1472, he married Sophia, daughter of Thomas Palæologus, and niece of Constantine XI, the last Emperor of Byzantium. The two heads symbolised the Eastern or Byzantine Empire and the Western or Roman Empire."