Kazimierz Siemienowicz

Kazimierz Siemienowicz (Latin: Casimirus Siemienowicz, Lithuanian: Kazimieras Simonavičius, Polish: Kazimierz Siemienowicz, born c. 1600 – c. 1651), was a Polish–Lithuanian general of artillery, gunsmith, military engineer, and pioneer of rocketry. Born in the Grand Duchy of Lithuania, he served the armies of the Polish–Lithuanian Commonwealth and of Frederick Henry, Prince of Orange, a ruler of the Netherlands. No portrait or detailed biography of him has survived and much of his life is a subject of dispute.

After contributing his expertise to several battles, Siemienowicz published Artis Magnae Artilleriae in 1650. This treatise, which discussed rocketry and pyrotechnics, remained a standard work in those fields for two centuries.

Due to the scarcity of documentary evidence, his place of birth and nationality are a matter of dispute between modern Lithuanian and Belarusian researchers.

The Lithuanian scientific school asserts that he was born near Raseiniai in Samogitia. The family, who was relatively poor, bore the Ostoja Coat of Arms with military service traditions in the Grand Duchy. In a book dedication, he refers to himself as an "Eques Lithuanus" (Lithuanian nobleman). Siemenowicz was educated in the Academy of Vilnius.

The Polish school, instead of defining his ethnicity, describes his identity simply as member of the szlachta (i.e., nobility in the Commonwealth) from Grand Duchy. Through some sources use the term "Polish," others describe him as "Lithuanian." Those terms should be understood in proper context: "Polish" means "of the Polish–Lithuanian Commonwealth"; "Lithuanian" from the Grand Duchy of Lithuania, a federal part of the Commonwealth. Polish historian Tadeusz Nowak described Siemienowicz as a Polonized Lithuanian nobleman. Polish historians for the most part accept that he used the Ostoja Coat of Arms and that he was an alumnus of the Academy of Vilnius.

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