Wikipedia
Dönhoff
Dönhoff, (Polish: Denhoff, sometimes also Doenhoff) was a noble German family, first mentioned in 1282, from the County of Mark in Westfalia; a branch moved to the Polish–Lithuanian Commonwealth in the 16th century and became recognized as szlachta (Polish nobility), but later mostly served the Prussian government. The main seat of the family from 1666 until 1945 was at Friedrichstein Palace in East Prussia.