Jan Stanisław Jankowski was a Polish politician, an important figure in the Polish civil resistance during World War II and a Government Delegate at Home. Arrested by the NKVD, he was sentenced in the Trial of the Sixteen and murdered in a Soviet prison.
Jankowski was born in the village of Krasowo Wielkie in Łomża Governorate, some 60 kilometres from Warsaw. Born to a family of local szlachta, he received an education in Austro-Hungarian Galicia. Early in his youth he became involved in politics. As a Socialist, in 1906 he was among the co-founders of the National Workers' Union. In 1912 he entered the KTSSN, a Galicia-based confederation of all the political factions supporting Austria-Hungary as the only state to be able to reunite and liberate Poland after roughly a century of partitions. In 1915, at the outbreak of the Great War, he joined the Polish Legions.
After Poland regained her independence in 1918, he remained an active politician. In 1920 he co-founded the National Workers' Party, which he headed until 1923 and of which he remained a deputy chairman until 1933.