Thule was the home of an Empire which a marauding Sphinx reigned over until it was overthrown by the Gallifreyan hero Prydonius. (PROSE: Cat's Cradle: Time's Crucible)

The Renegade Daleks had a base on Thule. Historians studying Dalek history found a damaged Supreme Dalek from the New Dalek Paradigm within the base, wondering if the Paradigm had interfered in the Imperial-Renegade Dalek Civil War. (PROSE: Dalek: The Astounding Untold History of the Greatest Enemies of the Universe)

The Academia Library on Gallifrey had a section dedicated to the "barbaric Empire of Thule". (PROSE: Cat's Cradle: Time's Crucible)