On Saturday, 23 December 1939, in the Jewish cemetery on Sienna Street in Lublin, the Germans murdered 10 representatives of the Polish intelligentsia, earlier imprisoned in the Castle Prison in November 1939.
Less than two months after the Germans occupied Lublin in September 1939, mass arrests of members of the Polish intelligentsia took place, which historians have referred to as Sonderaktion Lublin. The first people were arrested on 9 November 1939, i.e., on the same day that SS-Brigadeführer Odillo Globocnik became the head of the police and SS in the Lublin District of the General Government. The imprisoned Poles included the rector of the Catholic University of Lublin (KUL), Father Professor Antoni Szymański, presidents and vice-presidents of courts, and teachers of Lublin schools.
In the following days, the action was continued by the Germans. On 11 November, 14 scholars of the Catholic University of Lublin (KUL) were arrested, and the university itself was closed on 17 November, with the occupiers imprisoning several dozen of its students at the same time. On the same day, the Nazis raided the premises of the Bishop’s Curia in Lublin and arrested both bishops Marian Fulman and Władysław Goral, as well as several priests present in the buildings. All of them were tried before a German ad hoc court at the end of November and sentenced to death for illegal possession of weapons, organising Polish demonstrations on 11 November, the day of the restoration of independence (https://dignitynews.eu/pl/11-listopada-narodowe-swieto-niepodleglosci/).
Following the intervention of the Vatican, the sentences were changed to life imprisonment. In the following days, the Germans arrested other priests, teachers, and officials. Historians estimate that in November 1939, around 250 people were arrested in the Lublin region.
On Saturday 23 December 1939, 10 detainees were led out of the cells of the Lublin Castle Prison and taken to the area of the nearby old Jewish cemetery in Lublin. Two young criminal offenders were taken with them. They were all executed there. The murdered victims included Stanisław Bryła and Bolesław Sekutowicz – court presidents, Czesław Martyniak – professor at the Catholic University of Lublin (KUL), Father Michał Niechaj – professor at the Higher Seminary and the Catholic University of Lublin (KUL), Tadeusz Moniewski, Antoni Krzyżanowski – school directors, Józef Dańkowski – starost of Lublin, Tadeusz Illukiewicz – starost of Lubartów, Edward Lipski and Władysław Rutkowski – lawyers.