Thuban, or Aldib as it is sometimes called, is the Alpha Star of the Draco Constellation (Alpha Draconis), even though it no longer is the brightest star in the constellation. For a long time, it was the polar star in the Northern hemisphere.
The name "Thuban" is Arab for 'dragon' or 'lizard'.
Thuban is the home system of the Draconian Empire, and is inhabited by several lizard/reptilian and dinoid races. They were one of the first colonizing races in our Galaxy. It is when they tried to colonize the Lyran system that the Galactic Wars started more than 20 million years ago.
Barbara Hand Clow claims that Hizor is the original name of Thuban, and that it has a humanoid civilization as well. The Alpha Draconians would have been one of the extra-terrestrial races that had a permanent presence in Atlantis.
Because of their advanced technology, the fact that they are one of the oldest races in this Galaxy, and because they have literally created several races through genetic engineering, the inhabitants of Thuban like to call themselves Gods or Founders. (See Draco for more information).