Greiser was fanatically anti-Christian[1] and an early member of the Nazi Party (NSDAP number 166,635). After many years with the nationalist Deutschsoziale Partei (DtSP) founded by Richard Kunze and membership in the Stahlhelm in the mid-1920s, he joined the NSDAP and SA on 1 December 1929,[2] and the SS on 29 September 1931.[3]