The Meaning of Middle-earth
Middle-earth is used by Tolkien to desribe ‘the world of men’ in the imaginary world of his books. However, Tolkien believed that in order to create imaginary lands and stories, they must have their roots in reality. In an interview he once stated, ‘If you really want to know know what Middle-earth is based on, it's my wonder and delight in the Earth as it is, particularly the natural earth’. Tolkien's love of the Icelandic myths and the legends of the North meant he was very familiar with the expression as described below.
Miðgarðr is a name used in Old Norse literature. In Old English epic poetry it appears as Middangeard, later evolving as Middellaerd or Middle Earth in Middle English literature. It is a realm in Norse mythology somewhere in the middle of Yggdrasil, the world tree that links the realms of existence.
The tree of Yggdrasil had its roots extending below our realm of existence into the underworld. This was the third level – Hel, the world of the dead. The trunk grew through our world, the second level – the world of men, known as middle earth.The trees branches extended high above ours into the upperworld, the first level – Asgard the world of the gods.
As a warning for our times maybe, according to the ancient tales, middle earth will be destroyed at Ragnarok, the battle at the end of the world. Jormungadnr the giant serpent will rise from the ocean, poisoning the land and sea with his venom and causing the sea to rear up and lash against the land causing middle earth to sink below the waves.