Before Deliverance was freed by Corax, The Ravenspire was a tower inhabited by the guards of the guilds and was known as the Black Tower. It is noted to have a special torture floor called the Red Level and was banned by Corax sometime before the Horus Heresy. It is said that not even a Legionnaire could survive the punishments it holds.
After the Massacre at Isstvan V, Corax used the Ravenspire as as place to rebuild his legion with the Emperor's Gene tech. However, the gene tech would be lost in the Battle of Ravendelve against Alpha Legion Operatives and Tech-Guilds from Kiahavar.