Göksholm Göksholm is a medieval Swedish castle located on the southern beach of lake Hjälmaren . It is the oldest privately owned building in Sweden that has been continuously inhabited . Göksholm ' s oldest parts can be dated to the 13th century . It is located in Stora Mellösa , Örebro Municipality . Historically it is famous for the popular uprising ' s leader Engelbrekt Engelbrektsson , the then leader of the government ( " rikshövitsman " ) , having been murdered on its lands in 1436 by Måns Bengtsson , the son and heir of the then owner of the castle . Architectural history . In the middle ages Göksholm was just a fortified castle with a large tower . Its oldest existent parts have been dated to the 13th century . It was built ( rebuilt and enlarged ) during the Middle Ages through six different stages . After a fire at the end of the 16th century , the building was modernized according to that period ' s style , getting a more regular plan , bigger windows and details in the Dutch renaissance style . Despite the thorough renovation , the medieval base structure remains . A painted inner ceiling from the time of this renaissance renovation exists with 121 cassettes which is remarkably well preserved today . Under the 17th - century owners , Baron Knut Kurck and Baron Fleming , the castle was encrusted with portals , and circle - patterned outer buildings . Lars Gustaf Tersmeden had the ceiling renovated in 1801 . This was the last big change in its structure . Some facade details were changed in the 1950s . At that time , a study of the building ' s architectural history was undertaken by Iwar Andersson which has been published as " Göksholm — Från medeltida borg till nutida bostad " ( Kungliga Vitterhets Historie och Antikvitets Akademiens handlingar , Uppsala 1965 ) . List of Lords . Göksholm castle has always been private property . It was built as a medieval fortress to protect its owners , in much the same way as several medieval castles in other parts of Europe . The first attested owner of Göksholm ' s castle was Lady Ingeborg Ulfsdotter ( mentioned 1296 , died before 1307 ) , of the family of Ulv ( a cadet branch of the earl dynasty that later became known as the Folkunge royal line , or House of Bjellbo ) . ( She had " possibly " received it as her dower from her first husband , Lord Knut Mattsson of the family of Lejonbjälke , who was lawspeaker of Närke , the province where the castle is located . ) Göksholm was then passed down through four female generations . Great - great - granddaughter Lady Christina Magnusdotter brought it to her husband , Lord Bengt Stensson of the Ringhult lordship ( the family later dubbed Natt och Dag ) . The couple ' s son was the above mentioned killer , Lord Måns . There is an old list of castle owners , written in 1801 on the basis of a painted fris from 1676 which has since disappeared . It says that it contains all owners " who can be attested by written sources " throughout the period of c 1320 - 1676 . That list says : It is therefore incorrect as to the three first names . It appears obvious that medieval sources were not checked and that the male line had been extrapolated back from Bengt Stensson .