Kazimierz Siemienowicz was a general of artillery, gunsmith, military engineer, and one of pioneers of rocketry. Born in the Raseiniai region of the Grand Duchy of Lithuania, he served in the armies of the Polish–Lithuanian Commonwealth and of Frederick Henry, Prince of Orange, the ruler of the Dutch Republic. No portrait or detailed biography of him has survived and much of his life is a subject of dispute.

Artillery are ranged weapons that launch munitions far beyond the range and power of infantry firearms. Early artillery development focused on the ability to breach defensive walls and fortifications during sieges, and led to heavy, fairly immobile siege engines. As technology improved, lighter, more mobile field artillery cannons developed for battlefield use. This development continues today; modern self-propelled artillery vehicles are highly mobile weapons of great versatility generally providing the largest share of an army's total firepower.