What year did Heinrich Himmler join the unit that used the concept of Wehrbauer to refer to soldiers designated as settlers for the lands conquered during the German invasions of the Soviet Union and Poland?
Schutzstaffel The Schutzstaffel (SS; also stylized as with Armanen runes; ] ; literally "Protection Squadron") was a major paramilitary organization under Adolf Hitler and the Nazi Party (NSDAP) in Nazi Germany, and later throughout German-occupied Europe during World War II. It began with a small guard unit known as the "Saal-Schutz" (Hall-Protection) made up of NSDAP volunteers to provide security for party meetings in Munich. In 1925, Heinrich Himmler joined the unit, which had by then been reformed and given its final name. Under his direction (1929–45), it grew from a small paramilitary formation to one of the most powerful organizations in Nazi Germany. From 1929 until the regime's collapse in 1945, the SS was the foremost agency of security, surveillance, and terror within Germany and German-occupied Europe.
Ghetto uprising The ghetto uprisings during World War II were a series of armed revolts against the regime of Nazi Germany between 1941 and 1943 in the newly established Jewish ghettos across Nazi-occupied Europe. Following the German and Soviet invasion of Poland in September 1939, Polish Jews were targeted from the outset. Within months inside occupied Poland, the Germans created hundreds of ghettos in which they forced the Jews to live. The new ghettos were part of the German official policy of removing Jews from public life with the aim of economic exploitation. The combination of excess numbers of inmates, unsanitary conditions and lack of food resulted in a high death rate among them.  In most cities the Jewish underground resistance movements developed almost instantly, although ghettoization had severely limited their access to resources.