A Weeping Angel came to Gallifrey to steal information from the Matrix during the Cloister Wars. [source needed] It was trapped in the Cloisters by Fibre-optic cables and later used by the Matrix in an attempt to attack Clara, but she escaped. (TV: Hell Bent)
Later, after the Spy Master had brought Gallifrey to ruin thanks to learning about the Timeless Child, General Ko Sharmus destroyed all organic life still on Gallifrey with the death particle. (TV: The Timeless Children)