The second "Uranverein" began after the HWA squeezed out the "Reichsforschungsrat" (RFR, Reich Research Council) of the REM and started the formal German nuclear weapons project under military auspices. This second "Uranverein" was formed on 1 September 1939, the day World War II began, and had its first meeting on 16 September 1939. The meeting was organized by Kurt Diebner, advisor to the HWA, and held in Berlin. The invitees included Walther Bothe, Siegfried Flügge, Hans Geiger, Otto Hahn, Paul Harteck, Gerhard Hoffmann, Josef Mattauch, and Georg Stetter. A second meeting was held soon thereafter and included Klaus Clusius, Robert Döpel, Werner Heisenberg, and Carl Friedrich von Weizsäcker. Also at this time, the "Kaiser-Wilhelm Institut für Physik" (KWIP, Kaiser Wilhelm Institute for Physics, after World War II the Max Planck Institute for Physics), in Berlin-Dahlem, was placed under HWA authority, with Diebner as the administrative director, and the military control of the nuclear research commenced.