Sietje Gravendeel-Tammens (29 July 1914 – 27 September 2014) was a Dutch resistance leader and teacher. In 1944, she was sentenced to death, but survived because the sentence needed approval from Berlin. Biography Sietje Tammens was born on a farm near Kloosterburen as the oldest of eight children. At first she wanted to become a Dutch Reformed pastor despite not being raised religiously. Ultimately she chose to study at a training college to become a teacher. In 1939, she left for Groningen as a private teacher for a mentally handicapped son of a professor. During this period, she specialized in speech-language pathology. World War II In late 1941, Tammens became a teacher at a BLO school, special education for boys with learning difficulties. She found refuge for a Jewish boy from her school and his brother at a farm, which marked her first act of resistance. Her activities increased, and soon her house was used as a temporary shelter for refugees, and storage for stolen ration stamp and arms. In the summer of 1943, her house became the meeting place for the Groninger Top, the heads of the provincial resistance group. The Top consisted of five people of which Tammens was the sole female member, and had to vote on liquidations and armed actions. Her authority was never questioned, and she played a decisive role in determining reliability. On 14 July 1943, Tammens organized the raid on a ration stamp distribution centre in Langweer. On 31 December 1943 the police chief Anne Elsinga was killed because he had discovered that Trouw was printed in Bedum. His successor Jannes Keijer was killed four months later by the group. The executions resulted in the Silbertanne Represailles. In the early morning of 25 April 1944 about 1,000 soldiers and SD surrounded the villages of Zuidwolde, Bedum, Stedum, Winsum, and Middelstum. Six men were shot, and 148 were send to Nazi concentration camps, where 22 died. An attempted execution of Klaas Prenger, a NSB (Dutch nazi party) colleague at her school, failed. He was shot, but survived. Tammens had to flee. She first found refuge in Harlingen, and later in Leeuwarden. Using the false name Martha Oosterveen, she nevertheless continued with her resistance work. Arrest On 13 June 1944, Tammens and others were caught in a trap at the Identity Cards Office in Amsterdam, and were arrested. She was sent to Herzogenbusch concentration camp