In January 1929 Hitler appointed another senior Nazi Party member, Heinrich Himmler, to head the Schutzstaffel (SS), a paramilitary group founded in 1925 to serve as personal bodyguards to Hitler and other Nazis. Himmler set out to re-organise the SS, introducing a better system of organisation, and gathering intelligence on prominent Jews and Freemasons, as well as on rival political groups. In 1929 Himmler launched an SS recruitment campaign, and by the end of 1931 the group had 10,000 members. Himmler aimed to ensure that this membership was as racially Nordic as possible, establishing the SS Race and Settlement Main Office (RuSHA) to screen both applicants and the women whom SS members proposed to marry. In believing in the existence of a "Nordic" racial type which was the purest survival of the ancient Aryans, Himmler was influenced by the Nordicist ideas of Hans F. K. Günther (1891–1968), which had been popular in German nationalist circles over the preceding decades.