The Imperial Dalek mothership was the mothership of the Imperial Dalek faction commanded by Davros. It was known in the Daleks' own language as Eret-mensaiki Ska, which translated as "Destiny of Stars".
It was destroyed by the Hand of Omega. Davros was the only survivor, immediately fleeing from the ship when the Doctor refused to stop his attack. (TV: Remembrance of the Daleks) There were a number of escape pods on board the vessel. (PROSE: War of the Daleks; AUDIO: Terror Firma, Daleks Among Us)