The Rift first appears in the Doctor Who episode "The Unquiet Dead". This episode occurs in 1869, when the Gelth, gaseous humanoid organisms, pass through the Rift into a funeral parlour, where they can "possess" the corpses.
In the Doctor Who episode "The Unquiet Dead", which is set in 1869, the Gelth, a type of gaseous humanoid creature, travel through the Rift and enter a funeral home, where they are able to take control of deceased bodies.