Biblios was a library planet which collected all the known data of the universe except for weapons. It was tended by robot librarians.
The Vromyx and the Garynths each desired the data Biblios had collected on weapons and they fought to prevent the other from getting it, refusing to believe the robot librarians' claims that there were no such records. The war lasted for 47.63 years, preventing anyone else from gaining access to the library, until the Fourth Doctor arrived and learned of the situation from one of the librarians. He then blew up an empty storage building and told both the warring sides that it contained the super-weapon data, tricking them into assuming that there was nothing left to fight over. (COMIC: War of the Words)
In the 51st century, Jonathan Smith acquired on Biblios a diary entry by H. G. Wells describing the death of the Tenth Doctor at the hands of Smith himself. He was unaware that the Doctor had forged the entry so that he could capture Smith. (COMIC: The Time Machination)