Mussert collaborated with the German occupation government, but was granted little actual power and held the nominal title of Leider van het Nederlandsche Volk ("Leader of the Dutch People") from 1942 onwards.

[1] From an early age he showed talent in technical matters and after graduating from school he chose to study civil engineering at the Delft University of Technology.

A state of siege was declared by the Dutch government in April 1940 after the foreign correspondent for The New York Times, Vladimir Poliakov, reported that Mussert's followers were preparing to kidnap Queen Wilhelmina as part of a coup.

In February 1941, Mussert agreed to and oversaw the formation of the 23rd SS Volunteer Panzer Grenadier Division Nederland, which trained in Hamburg.

[5] After the Japanese invasion and occupation and the subsequent internment of 100,000 Dutch civilians and 50,000 military personnel, Mussert requested a meeting with Hitler.

On 13 December 1942, Hitler declared Mussert to be "Leider van het Nederlandse Volk" (Leader of the Dutch People).

Following the unsuccessful Operation Market Garden in September 1944, which included a supporting strike by Dutch railway workers, the German authorities forbade food transport by rail, resulting in the Hongerwinter of 1944/45 during which 18,000 died.

On 7 May 1946, exactly one year after his arrest and four days before his 52nd birthday, Mussert was executed by a firing squad on the Waalsdorpervlakte, a site near The Hague, where hundreds of Dutch citizens had been killed by the Nazi regime.