Alsnö hus

[1] The ruin is next to five burial mounds, up to 45 meters in diameter, which date back to the Vendel Period (i.e. Late Iron Age, c. 500-800 AD) when Hovgården was a King's Court (Kungsgård).

The royal castle Alsnö hus reflects the importance of Birka, the trade settlement on Björkö island just south of Adelsö.

However, Birka was abandoned around 975, but apparently the royal mansion continued to be of importance as the runestone U 11 (c. 1070 CE) was erected next to it.

[2] Alsnö hus first appears in historical records in 1200 as mansionem regiam Alsnu, i.e. a house of more than ordinary proportions.

However, 70 years later King Magnus Barnlock had the old fortress replaced by a summer residence built in brick.

The ruins of Alsnö hus on the island of Adelsö.
Reconstruction of the medieval brick building which covered 29x12 m. [ 3 ]