King Haakon and the Norwegian government escaped to Rotherhithe in London. Throughout the war they sent inspirational radio speeches and supported clandestine military actions in Norway against the Germans. On the day of the invasion, the leader of the small National-Socialist party Nasjonal Samling, Vidkun Quisling, tried to seize power, but was forced by the German occupiers to step aside. Real power was wielded by the leader of the German occupation authority, Reichskommissar Josef Terboven. Quisling, as ''minister president'', later formed a collaborationist government under German control. Up to 15,000 Norwegians volunteered to fight in German units, including the Waffen-SS.