Rosenfeldt estate was founded by Baron Reinhard von Iselin, a prosperous, Swiss-born landowner, who in 1774 acquired the land when the Crown sold Vordingborg Cavalry District by auction. From 1776 to 1777 he constructed a large farm complex around an octagonal courtyard with the assistance of the architect Christian Joseph Zuber. Iselin's daughter, Anna Elizabeth, inherited Rosenfeldt in 1781. In 1777 she had married the French-born nobleman Antoine de Bosc de la Calmette who in 1783 was appointed prefect of Møn where he owned Marienborg and founded the Liselund estate which he named after his wife.
In 1844 the estate was acquired by captain, general-major Oscar O´Neill Oxholm (1809-1871) who took up residency there with his Irish wife Adelaide Maria O´Kelly. Oxholm constructed the new main building, two farm buildings and 20 fæstegårde. Designed by Henrik Steffens Sibbern, the main building was built from 1868 to 1870. Rosenfeldt Manor is still owned by the Oxholm/Oxholm Tillischs family and covers 2,313 hectares
Rosenfeldt's buildings are arranged around seven of eight sides of Zuber's octagonal courtyard, a layout which is remniscient of that of Amalienborg in Copenhagen. Zuber's original farm complex consists of four low pavilions and two tall stable buildings in Neoclassical style. The plan also reserved a site for the main building which was not built until 1870. Sibbern's main building is constructed in red brick and designed in a Neo-Renaissance style. It consists of a two-story main wing with a tower flanked by two short lateral wings.
References:Sigmaringen Castle was first mentioned in the year 1077 in the chronicles of Petershausen monastery. The oldest parts of the castle are concealed beneath the alterations made during the 17th and the 19th centuries. The secret of the earliest settlement built on this defendable rock will never be fully revealed: large-scale excavation work would be necessary, which the extensive land development renders impossible. Judging from the many Roman remains unearthed in the area around Sigmaringen, the 12th century keep known as the 'Roman Tower' could be traced back to a Roman predecessor.
The castle remains that have been preserved (gate, great hall and keep) date back to the Staufer period around 1200. The castle remains were integrated into subsequent buildings. The foundations of the castle buildings are to a large extent identical to the surrounding castle wall.
These remains give us a good idea of how the castle might have looked during the 12th century.