The eagle symbolized strength, courage, farsightedness and immortality. It is considered to be the king of the air and the messenger of the highest Gods. Mythologically, it is connected by the Greeks with the God Zeus, by the Romans with Jupiter, by the Germanic tribes with Odin and by Americans with God.
An eagle can appear either single or double-headed. On at least one occasion a three-headed eagle is seen.
Iranian Empires (Persia) are among the first who used eagle as a standard. To the pagans, the eagle was an emblem of Jupiter, the god of the sky. The eagle and lion of Inishowen were used as Celtic drudic holy symbols. In 102 B.C. the Roman Consul Gaius Marius decreed that the eagle would be the symbol of the Senate and People of Rome. It is said that when the Second Temple of Jerusalem was being expanded and renovated in 20 B.C., Herod the Great offended the people by mounting a Roman golden eagle over the gate. When Herod died some years later, his opponents tore down the eagle. It is believed that the Prophet Muhammad’s first standard or flag in 7th century A.D. was a plain flag with no insignia on it to contradict the national standard of the opposing pagan Quraish tribe, Al-Uqaab, that had a black eagle on white background, the sacred Eagle that carried pagan prayers from Earth to the Sky.
Central Asian Turkish Shamans carried a wooden stick pole with seven or nine horizontal sticks forming stairs to an Eagle put on the top of the stick during their rituals. The eagle was regarded, for example, as a holy bird, a protective spirit, and the guardian of heaven. It was also a symbol of potency and fertility. Eagles on tombstones reflected the Shamanistic belief that the souls of the dead rose up to Heaven in the form of birds or were accompanied and protected by the eagle while traveling in the underworld and the sky. Eagle also was believed to be a carrier of prayers to the sky. The Altaic figures carved into rocks suggest that the eagle also was a sign of grandeur and magnificence among the Turks.
The Turkish shamanistic religious heritage of Asian roots survived to some extent after their acceptance of Islam and migration westwards. The metaphorical meaning of the name of Tougrul Beig (993-1063 A.D.) who founded the Seljuk State as its foremost commander was “Eagle”. The spirit of the Türkmen is accepted as 'horse' in the fifth and as “eagle” in the third period.
In mediæval and modern heraldry eagles are often said to indicate that the armiger (person bearing the arms) was courageous, a man of action and judicious. Where an eagle's wings were spread (“displayed”) it was said to indicate the bearer’s rôle as a protector. When mythological beasts are used, such as a griffin (part eagle, part lion) they indicate that the bearer of the arms possessed a combination of those animals’ qualities.
At the base of Ab-ú’s statue, found in the Old Sumerian shrine of Eshnunna (Tell Asmar), his symbol of a lion-headed eagle, with outstretched wings and talons, is shown as diving down upon his prey, arranged mirror-symmetrically. The lion-headed eagle was also known as the Ningirsu (storm-bird) in the Sumerian city of Lagash and said to have appeared as one or two lion-head eagles on recently excavated historical artifacts. The two-headed eagle later was an emblem of twin gods depicting power and omniscience. It appeared on monuments of the first Hittite Empire in central Anatolia and was an attribute of Nergal. Another very archaic Mesopotamian symbol that survived in Phoenician culture was the Gryphon, a mythical beast with the lower body of a lion and upper body of an eagle.
“And the pains of childbirth drove Mary to the trunk of a palm-tree: She cried in her anguish: 'Ah! would that I had died before this! would that I had been a thing forgotten and out of sight!' But (a voice) cried to her from beneath the palm-tree: 'Grieve not! for thy Lord hath provided a rivulet beneath thee. And shake towards thyself the trunk of the palm-tree: It will let fall fresh ripe dates upon thee. So eat and drink and cool thine eye. And if thou dost see any man, say, 'I have vowed a fast to Most Gracious, and this day will I enter into not talk with any human being'. At length she brought the (baby Jesus) to her people, carrying him in her arms. They said: 'O Mary! truly an amazing thing hast thou brought!' (19:23-27) (Moses) said (to the Pharaoh): 'He is the god of the East and the West, and all between; if you only had sense'(28:28) Now I do call to witness the Lord of all points in the East and the West (70:40) (He is) Lord of the East and the West: there is no god but He: take Him therefore for (thy) Disposer of Affairs (73:9)”.
Seljuk Turks, led by AlpArslan whose name meant "a valiant lion" and who was the nephew of Tougrul Beg, captured Jerusalem from the Egyptians in 1071, the same year as they entered Anatolia through Manzikert, introducing to the localities the bicephalous eagle standard of Seljuks of Rum (Roma) which transcended to generations from subsequent interface of nations through the crusades.
Another very popular eagle, used by Arab states today and historically, is the Saladin Golden Eagle. Used by Saladin in the 12th century, it is also used in the coats of arms of several Arab countries today, such as Egypt and Iraq.
According to Carl-Alexander von Volborth the first instance of the use of an eagle as an heraldic charge is the Great Seal of the Margrave Leopold IV of Austria in 1136. On the seal his figure carries a shield charged with an eagle. Also from about this time is a coin, minted in Maastricht (the Netherlands), dating from between 1172 and 1190 after contacts with the East via the crusades. It shows a single-headed eagle, see here
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.
Charlemagne was a Frankish ruler and the first Holy Roman Emperor from AD 800 - 814, well before the introduction of heraldry. In later periods, a coat of arms attributed to Charlemagne shows half of the body of a single-head black eagle as the symbol of the German emperors next to a fleur-de-lis as the symbol of the kings of France on an impaled shield.
The double-headed 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.
The Empire of Trebizond (1204-1461), one of the states created after the capture of Constantinople by the Fourth Crusade, used the emblem of the normal (single headed) eagle. The black eagle on yellow background is still used today in Greece by descendants of Pontian greeks.
Many modern states and individuals continue to use the eagle in their arms. These include:
In Spain the eagle, though it was first used by the Catholic monarchs as a symbol of Saint John the Evangelist, came to be associated with the regime of Francisco Franco and since his death has been removed from official usage.
The popular, informal term spread eagle is derived from a heraldic depiction of an eagle "displayed," with both wings, the body and the legs displayed, which has been used as the emblem of a number of states and monarchs.
Examples can be seen: