Heraldic eagle

The eagle is used in heraldry as a charge, as a supporter, and as a crest. The eagle with its keen eyes symbolized perspicacity, courage, strength and immortality, but is also considered "king of the skies" and messenger of the highest gods. With these attributed qualities the eagle became a symbol of power and strength in Ancient Rome. Mythologically, it has been connected by the Greeks with the God Zeus, by the Romans with Jupiter, by the Germanic tribes with Odin, by the Judeo-Christian scriptures with those who hope in God (Isaiah 40:31), and in Christian art with Saint John the Evangelist.

The eagle as a symbol has a history much longer than that of heraldry itself. In Ancient Egypt, the falcon was the symbol of Horus, and in Roman polytheism of Jupiter. An eagle appears on the battle standard of Cyrus the Great in Persia, around 540 BC. The eagle as a "heraldic animal" of the Roman Republic was introduced in 102 BC by consul Gaius Marius. According to Islamic tradition, the Black Standard of Muhammad was known as راية العُقاب (rāyat al-ʿuqāb) "banner of the eagle" (even though it did not depict an eagle and was solid black). In Christian symbolism the four living creatures of scripture (a man, an ox, a lion, and an eagle) have traditionally been associated with the Four Evangelists. The eagle is the symbol of Saint John the Evangelist.

...
Wikipedia