Some people believe that what we now call the Asteroid Belt is not a collection of asteroids, but rather the remains of a planet that has been completely obliterated. What planet the Asteroid Belt is the remains of is up for debate.
There was said to have been a great war between two technologically advanced groups of beings in our ancient history and this war resulted in the destruction of a planet called Tiamat. 1/2 of Tiamat became the Asteroid Belt while the other 1/2 became Earth.
