In J. R. R. Tolkien's Middle-earth, the Eagles or Great Eagles, are immense birds that are sapient and can speak. The Great Eagles resemble actual eagles, but are much larger. Thorondor is said to have been the greatest of all birds, with a wingspan of 30 fathoms. Elsewhere, the Eagles have varied in nature and size both within Tolkien's writings and in later adaptations.
Tolkien based his painting of an eagle in The Hobbit on this 1919 illustration of an immature golden eagle by Archibald Thorburn.
The Norse god Odin, like Gandalf, was associated with eagles. A bird with a hooked beak beside Odin (named as houaz, "the high") on a bracteate from Funen, Denmark
Scholars have linked the Eagles to Christianity, one connection being that an Eagle is John the Evangelist's traditional symbol. Icon of St John with eagle, Kazan Cathedral, St. Petersburg
Middle-earth is the setting of much of the English writer J. R. R. Tolkien's fantasy. The term is equivalent to the Miðgarðr of Norse mythology and Middangeard in Old English works, including Beowulf. Middle-earth is the human-inhabited world, that is, the central continent of the Earth, in Tolkien's imagined mythological past. Tolkien's most widely read works, The Hobbit and The Lord of the Rings, are set entirely in Middle-earth. "Middle-earth" has also become a short-hand term for Tolkien's legendarium, his large body of fantasy writings, and for the entirety of his fictional world.
A detail of Middle-earth in one of Peter Jackson's film sets
Medieval Christian cosmology: heaven above, earth in the middle, hell below. Vank Cathedral, Isfahan.