Arda

Arda was the name given to the World in J.R.R. Tolkien's legendarium, the realm made by the Ainur at the bidding of Eru Ilúvatar and the stage upon which all the histories of the Elves, Men, Dwarves, and other peoples unfolded. Middle-earth was but one part of it.

Making

Arda came into being from the Music of the Ainur and the vision Eru showed them, and was given true existence when Eru uttered the word Eä, "Let it Be". Many of the Ainur then entered into Arda to shape and govern it; the greatest of these were the Valar. They laboured long to order the world, raising mountains and seas and kindling lights, though their works were ever marred and contested by Morgoth, whose evil ran so deep that the whole of Arda was said to be tainted by it (the "Marring of Arda").

Shape

In its early ages Arda was conceived as a flat world, lit first by lamps and then by the Two Trees of Valinor, and later by the Sun and Moon. It contained the continent of Aman in the West, where Valinor lay; Middle-earth in the centre; and other lands east and south. At the Downfall of Númenor, Eru changed the very shape of the world, making it round and removing Aman from its circles, so that mortal ships could no longer sail to the Undying Lands.

Significance

Arda was the whole sphere of the world's history. Within it the Valar dwelt, the Children of Ilúvatar awoke, and the long struggle against the Shadow, from Morgoth to Sauron, was waged across the ages. It was destined to endure until the end foretold in prophecy, the Last Battle and the remaking of the world.