Hermann Gradnauer was born in Wolfenbüttel in 1894 as the son of a shoe merchant. After serving in the military as a medic until 1918, he studied dentistry and started working as a dentist in Hamelin in 1920. His wife Hilde Gradnauer, née Ilberg, also came from Wolfenbüttel, where her parents ran a leading textile business. The couple had two children.
The Zionist Youth Movement in which Gradnauer grew up in Wolfenbüttel had a major influence on him early on. He was a leading member of the Young Jewish Hiking Association (Jung-Jüdischer Wanderbund/JJWB) founded in 1920 and in 1922, he was one of the founders of the socialist Brit Haolim. At two meetings in Wolfenbüttel on March 11 and March 24-25, 1923, Gradnauer was successful in having a splinter group of the Jewish hiking organization Blue-White (Blau-Weiß), the “Free Jewish hiking organization Blau-Weiß”, align itself with the young Brit Haolim. This included the Blue-White (Blau-Weiß) group from Emden under the leadership of Alfred van der Walde. It was likely due to Gradnauer’s influence that the national convention for Brit Haolim was held on the Ohrberg near Hamelin on July 28-29, 1923. It was also likely his idea to found Zentrum Hameln (Center Hamelin) spread over different villages.
In 1924 Gradnauer went with his wife and daughter to the socialist kibbutz Ein Harod in northern Palestine. Brit Haolim had had early contacts to Ein Harod, which had been founded in 1921 by Russian Jews. As a dentist, he was able to do this without having to have undergone a lengthy agricultural training.
At the end of 1925, the family returned to Hamelin. The Zentrum Hameln, the predecessor to kibbutz Herut, was already being established at the time and was recruiting members. In Hamelin Gradnauer again worked as a dentist and took over the organizational management of the Zentrum Hameln, later kibbutz Herut.
As an adult professional family man and Palestine pioneer, Gradnauer played an important role for many of the often very young hawerim (“We called him “aba”, father.”) His stern appearances were a hallmark of the weekend meetings of Herut. For others like Alice Fass, Gradnauer’s authoritarian behavior was difficult to bear.
Hermann Gradnauer died in 1972 at kibbutz Givat Brenner in Israel.