as “Leider van het Nederlandse Volk” (Leader of the Dutch People) NS in December 1942, he was allowed to form a national government institute, a Dutch shadow cabinet called “Gemachtigden van den Leider“, which would advise Reichskommissar Arthur Seyss-Inquart from 1 February 1943. The institute would consist of a number of deputies in charge of defined functions or departments within the administration.
On 4 February Retired General and Rijkscommissaris Hendrik Seyffardt, already head of the Dutch SS volunteer group Vrijwilligerslegioen Nederland, was announced through the press as “Deputy for Special Services”. As a result, the Communist resistance group CS-6 under Dr. Gerrit Willem Kastein (named after its address, 6 Corelli Street, in Amsterdam), concluded that the new institute would eventually lead to a National-Socialist government, which would then introduce general conscription to enable the call-up of Dutch nationals to the Eastern Front. However, in reality the Nazis only saw Mussert and the NSB as a useful Dutch tool to enable general co-operation, and furthermore, Seyss-Inquart had assured Mussert after his December 1942 meeting with Hitler that general conscription was not on the agenda. However, CS-6 assessed that Seyffardt was the most important person within the new institute who was eligible for an attack, after the heavily-protected Mussert.
After approval from the Dutch government in exile in London, on the evening of Friday 5 February 1943, after answering a knock at his front door in Scheveningen, Den Haag Seyffardt was shot twice by student Jan Verleun who had accompanied Dr. Kastein on the mission. A day later Seyffardt succumbed to his injuries in hospital. A private military ceremony was arranged at the Binnenhof , attended by family and friends and with Mussert in attendance, after which Seyffardt was cremated. On 7 February, CS-6 shot fellow institute member “Gemachtigde voor de Volksvoorlichting” (Attorney for the national relations) Hermannus Reydon and his wife. His wife died on the spot, while Reydon on died on 24 August of his injuries. The gun used in this attack had been given to Dr. Kastein by Sicherheitsdienst, SD agent Anton van der Waal’s , who after tracking him back through information, arrested him on 19 February. Two days later Dr. Kastein committed suicide so as not to give away Dutch Resistance information under torture. One of them was Operation Silbertanne victim Christiaan de Jong.
Seyffardt and Reydon’s deaths led to massive Nazi Germany reprisals in the occupied Netherlands, under Operation Silbertanne, supported by various German officers. Silbertanne was intended as reprisal for the attacks made on predominantly Dutch collaborators and German occupational forces by the Dutch resistance.
SS General for the Netherlands Hanns Albin Rauter gave order to retaliate by assassinating civilians presumed to be in some way connected to the resistance or to be orange minded, meaning Dutch patriots, or anti-German. The task of perpetrating the killings was first assigned to especially formed death squads, though killings were later carried out exclusively by Sonderkommando Johannes Feldmeijer, a special unit consisting of 15 SS-members.
Rauter immediately ordered the murder of 50 Dutch hostages and a series of raids on Dutch universities. By accident the Dutch resistance had attacked Rauter’s car on 6 March 1945, which in turn led to the killings at De Woeste Hoeve, massacre, where 117 Duch men and one German soldier Ernst Gräwe were rounded up and executed at the site of the ambush and another 147 Gestapo prisoners executed elsewhere..The first killings took place in autumn 1943 in Meppel and Staphorst, and within a year more than 54 Dutchmen had been murdered or severely wounded. On 1–2 October 1944, in the village of Putten, over 600 men were deported to camps to be killed in retaliation for resistance activity in the Putten Raid Some of the most notorious Dutch war criminals participated in Operation Silbertanne: Heinrich Boere Maarten Kuiper ,Sander Borgers, Klaas Carel Faber , his brother Pieter Johan Faber , Daniel Bernard, a criminal man and Lambertus van Gog..
One of the most prominent victims of Operation Silbertanne was Dutch writer Adrianus Michiel de Jong , who was killed in October 1943.
Mussert was fundamentally opposed to Operation Silbertanne, and when in autumn 1944 SS Brigadeführer Karl Ebenhard Schöngarth, head of SiPo and SD was informed of these retaliatory killings he had them terminated in September 1944.
After World War II, some of the members of the death squad and those responsible for giving the orders were put on trial. Henk Feldmeijer, however, had been killed in the war. Maarten Kuiper and Pieter Johan Faber were executed in 1948. Hanns Albin Rauter was sentenced to death and executed in 1949. Others, however, managed to flee the country and went into hiding outside the Netherlands. Sander Borgers died in 1985 at the age of 67 in Haren, Germany, Klaas Carel Faber lived until his death on May 24, 2012 in the Bavarian city of Ingolstadt. In July 2009 it was reported that the German government wanted to prosecute Faber after all.Daniel Bernhard died in 1962. Lambertus van Gog fled to Spain but was extradited to the Netherlands in 1978. Heinrich Boere, who has been living for decades in Germany, was found fit to stand trial for the murders committed between 1943 and 1944, by the Provincial Court of Appeal in Cologne on 7 July 2009, and subsequently was found guilty and sentenced to life in prison in March 2010. Boere died in a prison hospital on December 1, 2013.