On 26 July 1941, the Germans murdered Prof. Kazimierz Bartel, an eminent mathematician, politician and five-time Prime Minister of Poland in the inter-war period, together with a group of prisoners in Piaski Janowskie near Lwów (today’s Lviv).

Kazimierz Bartel was born on 3 March 1882 in Lwów. In his home city, in 1909, he completed his studies at the Faculty of Mechanical Engineering at the Lwow University of Technology and started working there, swiftly obtaining further scientific degrees (in 1911, he became a doctor, and in 1913 – a professor of descriptive geometry). After the outbreak of the First World War, he fought for the Austro-Hungarian army. When the war ended, he returned to his home city and joined the ranks of the nascent Polish Army. He took part in the Polish-Ukrainian battles as commander of the railway troops and commander of the Main Railway Station. From December 1919, he held the post of Minister of Railways for a year. This was the period of the Polish-Bolshevik War (1919-1921), in which rail transport played a key role in redeploying the army and evacuating civilians from threatened areas.

From 1922 to 1929, he was a member of the Polish Parliament. After the May Coup of 1926 by Marshal Józef Piłsudski, Bartel became Prime Minister of the Government. By 1930, he had been Prime Minister five times.

In 1929, he was elected Rector of the Lwów University of Technology. He also held the post of president of the Polish Mathematical Society. In the 1930s, he fiercely opposed anti-Semitic speeches in Lwów, as well as on the university premises. After the German attack on Poland in September 1939, he headed the Civic Committee in Lwów. After the Soviet Union occupied the city in 1939, he was allowed to teach at his home university. After the German aggression against the Soviet Union, Lwów was occupied on 30 June 1941, and two days later Kazimierz Bartel was arrested. He was taken to the Gestapo prison on Łącki Street. Less than a month later, on 26 July 1941, he was executed on the personal order of Heinrich Himmler. Earlier in Lwów, on 4 July 1941, the Germans had murdered several dozen professors of Lwów universities and members of their families.