In 1246, with the support of the Papacy, he was elected King of Germany in opposition to Conrad IV, but his contested reign lasted a mere nine months.

After Pope Innocent IV imposed a ban on Frederick in 1245, Raspe changed sides, and on 22 May 1246 he was elected anti-king in opposition to Conrad.

[2] The strong papal prodding that led to his election earned Raspe the derogatory moniker of "Pfaffenkönig" (priests' king).

[4] In August 1246 Henry defeated Conrad in the Battle of Nidda in southern Hesse, and laid siege to Ulm and Reutlingen.

[9] After his death, the Emperor enfeoffed Thuringia to Henry III, Margrave of Meissen, the son of his sister Jutta.