About Paweł Jasienica
Paweł Jasienica was the pen name of Leon Lech Beynar (10 November 1909 – 19 August 1970), a Polish historian, journalist, essayist and soldier. During World War II, Jasienica (then, Leon Beynar) fought in the Polish Army, and later, the Home Army resistance. Near the end of the war, he was also working with the anti-Soviet resistance, which later led to him taking up a new name, Paweł Jasienica, to hide from the communist government of the People's Republic of Poland. He was associated with the Tygodnik Powszechny weekly and several other newspapers and magazines. He is best known for his 1960s books on Polish history—on the Kingdom of Poland under the Piast dynasty, the Jagiellon dynasty, and the elected kings of the Polish–Lithuanian Commonwealth. Those books, still popular, played an important role in popularizing Polish history among several generations of readers. Jasienica became an outspoken critic of the censorship in the People's Republic of Poland, and as a notable dissident, he was persecuted by the government. He was subject to significant invigilation (oversight) by the security services, and his second wife was in fact an agent of the communist secret police. For a brief period marking the end of his life, his books were prohibited from being distributed or printed. In 1935 he published his first history book – about King Sigismund II Augustus, Zygmunt August na ziemiach dawnego Wielkiego Księstwa (Sigismund Augustus on the Lands of the Former Grand Duchy ).
Biography source: Wikipedia. The profile adds birthday-specific historical context from the Celebs Birthday Today editorial database.