From TARDIS Index File, the free Doctor Who reference.
Galaxy 4 is the location of the planet Drahva. Another planet was located in the galaxy, but it ended in 14 planetary cycles. (DW: Galaxy 4)
- Galaxy 4 may be one of the Ten Galaxies ruled by the Dominators (DW: The Dominators) and may be the same galaxy as the Fourth Galaxy, which allied itself with the Daleks. (DW: The Daleks' Master Plan)