According to Snorri Sturluson, Konghelle was the location of two important royal summits to conclude peace between Sweden and Norway.
Konghelle appears in writings by the English chronicler, Orderic Vitalis, who named the city as one of six Norwegian civitates.
[2] The city was a center of royal authority during the early Middle Ages and especially the 13th century, when it was the Norwegian kingdom's southernmost outpost.
In 1256 Norwegian King Haakon IV of Norway had invaded Halland, at that time a province held by Denmark.
[3] In the early 14th century, Konghelle was the fief of Duke Erik Magnusson, father of Magnus Eriksson, the future king of Sweden and Norway.
[4][5] After the construction of the stronghold Bohus in 1308 by King Haakon V, the castle on Ragnhildsholmen started to lose its importance as a royal seat.
[6] Archaeological excavations began in the late 19th century at Ragnhildsholmen and the monastery of Kastelle kloster site and continue to the present day.
[11] The found of the remains of the hall building is believed to be a precursor to the royal estate that is mentioned in several sources, including in Njáls saga from the 13th century.