A dissertation submitted at the Rijksuniversiteit Leiden in 1937 established Gerrit Kastein as a practitioner in neurology. While he began his career within the confines of medicine, his professional trajectory shifted during the 1930s as he became an outspoken communist, later transitioning into a pivotal figure within the Dutch resistance during the Second World War.
Political Engagement and Early Medical Career
Born in Zutphen in 1910 to Albertus Gerhardus Kastein and Gerdina Leurink, Kastein pursued advanced medical training. His commitment to communist ideology prompted regular monitoring by Dutch authorities throughout the 1930s. He traveled to the Spanish Civil War to serve as a physician with a Dutch ambulance unit. Upon returning to the Netherlands, he integrated his medical practice with his political activities, eventually providing care to fellow communist Arie Kloostra following a violent demonstration in The Hague.
Twenty questions, eight minutes on the clock, and a percentile measured against everyone who has taken it. No sign-up.
Take the IQ test →Leadership of the CS-6 Group
Following the Dutch capitulation, Kastein participated in the 17 May 1940 inaugural meeting of The Hague branch of the CPN. He helped form the Spark Group and initiated medical resistance efforts. By 1941, he had gone into hiding and founded CS-6, a resistance cell based at Corellistraat 6 in Amsterdam. The group included members such as Jan Verleun, Pam Pooters, and the Boissevain brothers. Kastein gathered intelligence on German coastal defenses, though his efforts were undermined by the infiltration of Sicherheitsdienst double agent Anton van der Waals.
Targeted Attacks on Nazi Collaborators
In early 1943, CS-6 identified high-ranking collaborators within the Gemachtigden van den Leider, a shadow cabinet formed to assist Reichskommissar Arthur Seyss-Inquart. On 5 February, Kastein and Jan Verleun executed the assassination of General Hendrik Seyffardt in Scheveningen. Two days later, the group targeted Hermannus Reydon and his wife. These operations relied on weapons sourced through Van der Waals, who manipulated the group to track their movements and trigger German reprisal policies known as Operation Silbertanne.
Final Arrest and Death
Kastein was apprehended on 19 February 1943 at De Kroon public house in Delft, following the arrest and compromise of associate Piet Wapperom. During subsequent interrogations, Kastein engaged in multiple physical struggles with his captors, wounding agents Ernst Knorr and Martin Kohlen. While held in an interrogation room at the Binnenhof, Kastein attempted to escape by jumping through a second-floor window. The fall resulted in a fractured skull, and he died from his injuries hours later.
Fast facts
- Born: 1910, Zutphen
- Died: 1943, The Hague
- Education: Rijksuniversiteit Leiden
- Key Organization: CS-6
- Citizenship: Kingdom of the Netherlands
- Award: Dutch Cross of Resistance
Questions readers ask
What role did Gerrit Kastein play in the resistance?
He was a founding member of the CS-6 resistance group and organized intelligence gathering on German coastal defenses.
How did Kastein die?
He sustained a fatal skull fracture after leaping from a second-story window while in custody at the Binnenhof in 1943.
