In around 1300 Sostrup was an outlying farm known as Svorttorp but the first written record dates from 1388. The current castle was built in 1586 by councillor Jacob Seefeld. In 1807 the castle was bought by the Danish State and in 1829 by Jakob von Benzon. After this period some changes and restorations were made until the Danish State went into possession again in 1945. In 1946 it was run as a refugee camp. In 1960 the castle was bought by the Danish Cistercian Order. The castle was totally restored and today it is run as a conference centre.
References:House of the Blackheads (Melngalvju nams) is a building situated in the old town of Riga. The original building was erected during the first third of the 14th century for the Brotherhood of Blackheads, a guild for unmarried German merchants in Riga. Major works were done in the years 1580 and 1886, adding most of the ornaments.
The structure was bombed to a ruin by the Germans June 28, 1941 and the remains demolished by the Soviets in 1948. The current reconstruction was erected from 1995 to 1999. Today the House of Blackheads serves as a museum and sometimes concert hall.