In 1934, (PROSE: Timewyrm: Exodus) the Fifth Doctor met Himmler and Reinhard Heydrich while pursuing the Master across Berlin during the Night of the Long Knives. The Doctor actually considered both men pleasant company but sometimes thought back to the occasion wishing he had asked for a gun and shot them both to prevent the crimes they would commit. (PROSE: The King of Terror)
In 1939, the Seventh Doctor met Himmler at a party rally in Nuremberg. Himmler was initially suspicious of the Doctor until he convinced him that he was a secret occult master. Himmler then told the Doctor about the Black Coven at Drachensberg. (PROSE: Timewyrm: Exodus)
In 1940, Himmler sent a representative, SS Brigadier General Kraus, to the Le Mur Engineering compound in Nazi-occupied Jersey to receive a report on the Cybermen found there. Said discovery also caused a power struggle in Berlin where Himmler, Hermann Goering, Rudolf Hess and others all sought a position under the Führer that would place them in charge of the discovery. (PROSE: Illegal Alien)
He considered himself a modern King Arthur, searching with his SS knights for the Holy Grail. In 1944, Himmler acquired the Scrying Glass from Colonel Otto Klein and began attempting to learn its secrets.
On 20 April 1945 as the Allies surrounded Berlin, Himmler recognised the insanity of Hitler's insistence that the German forces fight on and left the Fuhrerbunker in an unauthorised attempt to negotiate peace. The Allied forces recognised Himmler immediately and arrested him. Hitler found out about this on 28 April and branded Himmler a traitor.
After the war, Himmler was one of twenty-three senior Nazis to be put on trial at Nuremberg between 1945 and 1946, but he committed suicide before his trial could take place. (PROSE: The Shadow in the Glass)