Kazimierz Siemienowicz

Kazimierz Siemienowicz (c. 1600–c. 1651) was a Polish–Lithuanian general of artillery, military engineer and a pioneer of rocketry, born in the Raseiniai region of the Grand Duchy of Lithuania. He fought in the Smolensk War of 1632–1634, served Frederick Henry of Orange and took part in the Siege of Hulst in 1645.

He returned in 1646 as King Władysław IV gathered specialists, and became second-in-command of the Royal Artillery in 1648. Around 1649 he settled in Amsterdam, where in 1650 he published the treatise Artis Magnae Artilleriae on artillery, rockets and pyrotechnics, a standard handbook for two centuries.