Alternate Nazi Germany

Alternate Nazi Germanies existed at many times, either created in alternate timelines or as natural parallel universes.

Known Worlds
During the War in Heaven, there were many Known Worlds where the Nazi Germany won World War II. Designated as "Germanias", these were collected into the Greater German Reich. (PROSE: Warlords of Utopia)

Elizabeth Klein's Nazi Germany
In an alternative timeline accidentally created by the Seventh Doctor and Ace's arrival in Colditz Castle in October 1944, Nazi scientists used the laser technology contained in Ace's Walkman to refine uranium and create nuclear weapons. They subsequently bombed New York City and Moscow, forcing the surrender of the United States and the Soviet Union and winning Germany the war. This timeline was negated by an alternative version of the Eighth Doctor who, while posing as a German scientist named Johann Schmidt, fabricated a "flight log" for the TARDIS and manipulated Elizabeth Klein into travelling back in time to Colditz in October 1944 on the pretext of retrieving the Doctor so that he could teach her to pilot the TARDIS. Her lover Major Jonas Faber saw through Schmidt's trickery but was too late as Klein had already decided to disobey his orders and make the trip into the past. Unfortunately for Klein, her arrival in Colditz alerted the Seventh Doctor to the impending alteration of history and he and Ace were able to prevent it. (AUDIO: Colditz, Klein's Story)

The so-called "Thousand Year Reich"
In an alternative timeline in which Hitler did not lose the power of the Timewyrm, Germany had conquered the United Kingdom and the rest of Europe by 1941. After visiting the occupied London in May 1951 in this timeline, the Seventh Doctor and Ace prevented this from coming to pass. (PROSE: Timewyrm: Exodus)