Kasper Doenhoff
Prince Kasper Doenhoff (German: Kaspar von Dönhoff, Polish: Kacper Denhoff, 1587–1645) was a Polish nobleman of Baltic-German extraction, a Reichsfürst of the Holy Roman Empire and Governor of Dorpat Province within the Polish–Lithuanian Commonwealth. Upon converting to Catholicism, he became a trusted courtier and advisor to Sigismund III of Poland.