In all, five people held the title of Reichsführer-SS during the twenty years of its existence.
Three persons held the position as a title while two held the actual SS rank.

Hanke was appointed SS leader in April 1945, but not informed until early May. He was captured by Czech partisans on 6 May and interned.
He was killed on 8 June, while attempting to escape a POW camp.
Historians have often speculated that Reinhard Heydrich would have eventually held the rank had Himmler in some way been killed or removed from his position earlier in World War II, and indeed Heydrich was often seen as Himmler's heir apparent by senior SS leaders.
However, at a diplomatic function in Italy in 1941, Heydrich was reported as stating that he had no desire to succeed Himmler.
In all, five people held the title of Reichsführer-SS during the twenty years of its existence. Three persons held the position as a title while two held the actual SS rank.
Hanke was appointed SS leader in April 1945, but not informed until early May. He was captured by Czech partisans on 6 May and interned. He was killed on 8 June, while attempting to escape a POW camp. Historians have often speculated that Reinhard Heydrich would have eventually held the rank had Himmler in some way been killed or removed from his position earlier in World War II, and indeed Heydrich was often seen as Himmler's heir apparent by senior SS leaders. However, at a diplomatic function in Italy in 1941, Heydrich was reported as stating that he had no desire to succeed Himmler.
Reichsführer-SS