The Sanctuary is a domain of Thanos.
After falling from the Bifrost Bridge, Loki is transported to the Sanctuary. There, Thanos teaches Loki how to control the mind. Later, The Other informs Thanos that Loki is ready to lead the Chitauri troops. Before Loki stole the Iridium, The Other tells Loki that if he fails Thanos will show him what is the real pain. During the Chitauri invasion, Iron Man puts a nuclear bomb in the Chitauri space, exploiting the Chitauri Command Center and thus stopping the invasion.
After the capture of Gamora by Nova Corps, The Other calls Ronan to inform the Gamora's betrayal and also inform him that Thanos wished to speak with him immediately. Already in the Sanctuary, a confused Ronan not understand why Thanos wanted to talk with him being that Gamora had been responsible for the loss of the Orb, but the Other argues that he is responsible and tells him to lower his tone in the presence of Thanos, Ronan gets angry and kills the Other.
Ronan asks him to take seriously the Gamora's betrayal but Thanos replied that the only thing does not matter it was him and acts like a putty child and threatens him saying he bathe the starways with his blood if he returns with empty hands again. Ronan is ready to fight, but Nebula stops him, saying that this fight he can not win, Nebula and Ronan leave and Thanos away smiling on his floating throne.