The Neuhardenberg estate (formerly Quilitz) was owned by the family of the Herrenmeister of the Order of Saint John Albrecht Friedrich of Brandenburg-Sonnenburg from 1696 to 1762. In the 18th century, General v. Prittwitz built a castle, of which Frederick the Great is said to have remarked: ’He is building a castle! He’s aiming high!’
In 1814, State Chancellor Karl August Prince von Hardenberg received the property as an endowment from the King. He had it rebuilt in a classical style by Karl Friedrich Schinkel in 1820-23. The landscape garden was redesigned in 1821 by Hermann von Pückler-Muskau with the assistance of Peter Joseph Lenné.
In 1944, Knight Carl-Hans Graf von Hardenberg took part in resistance activities against the Nazi regime. From his residence at Schloss Neuhardenberg, he was involved in organising the assassination attempt on Hitler in July 1944, which, however, failed. After a failed suicide attempt, he was imprisoned in Sachsenhausen concentration camp. The Red Army liberated the camp before his death sentence could be carried out. From 1948 to 1958, Count von Hardenberg headed the Brandenburg Provincial Cooperative of the Order of St John as Commendator.
