The manor of Ekolsund was established in the 1300s. The first known owner was the council Magnus Knutsson, mentioned in 1351. In the 1500s the castle came into royal hands when King Gustav Vasa took over the ownership. It was in 1578-1611 the residence of Princess Sophia of Sweden.
The crown anyway donated Ekolsund to Åke Tott in 1618. Ekolsund was moved again to the Crown during Karl XI’s reduction, and in 1716 it was appointed to Landgraf Fredrik of Hessen-Kassel (later Fredik I). In 1747 it was sold to Prince Adolf Fredrik on the account of the new heir Gustav (later Gustav III). In 1785, Ekolsund was sold from the hands of the Crown to George Seton, a man of Scotish heritage. In 1917 it was bought by Carl Kempe. In 2002, Ekolsund was bought by a private firm.
Both southern and northern castle was built in the middle of the 1600s, excedran came centuries later. Architects were Simon de la Vallée, Nicodemus Tessin the Elder, Carl Harleman, Carl Fredrik Adelcrantz and Jean Eric Rehn.
References:The Château du Haut-Koenigsbourg is situated in a strategic area on a rocky spur overlooking the Upper Rhine Plain, it was used by successive powers from the Middle Ages until the Thirty Years' War when it was abandoned. From 1900 to 1908 it was rebuilt at the behest of the German kaiser Wilhelm II. Today it is a major tourist site, attracting more than 500,000 visitors a year.
The first records of a castle built by the Hohenstaufens date back to 1147. The fortress changed its name to Koenigsburg (royal castle) around 1157. The castle was handed over to the Tiersteins by the Habsburgs following its destruction in 1462. They rebuilt and enlarged it, installing a defensive system designed to withstand artillery fire.
The fortification work accomplished over the 15th century did not suffice to keep the Swedish artillery at bay during the Thirty Years War, and the defences were overrun.