In Erik Chronicles, which was taken down a bit into the 1300s is to read about the advent of the Norwegian fortress Bohus. Construction began in 1308 on the orders of the country's King Haakon Hålägg and was a well terrain suited ring wall castle, built in defence of Norway's southern border and is situated where Nordre River flowing west from Göta River, and then transforms Hisingen to an island
The fortress said in its earliest parts had to been of timber, but already in 1330 had Magnus Eriksson - union king of Norway and Sweden - construct a new castle of stone. Much of the building material was extracted from Ragnhildsholmen at Kongahälla, the predecessor to the Bohus bail which is believed to have been abandoned by the year 1319.
The name Bohus is likely to be derived from the old Norwegian word bagi meaning barriers, aimed at the island where the fort was built. Originally, it was called Elfabagi, pretty soon Bagaholm, later Bagahus and finally Bahus or Bohus.
Once the Viking ships sailed past the cliff where the Bohus Fortress today sit with dignity.
Bohus dominant position is on a 40 meter high cliff which gave it a great overview of both Göta and Nordre River, and the rivers worked as perfectly natural moats of the fortress.
The meeting here of summer 1101 is the first time that the border between Norway and Sweden is mentioned, as well as a meeting where the tree kings at the same time met to negotiate.
The King was, Inge Stenkilsson Elder from Sweden, Erik Ejegod from Denmark, and Magnus Barfot from Norway. The meeting has been documented that have taken place in the river, probably outside the Kongahälla and so on Norwegian territory.
"Peace of Kongahälla," came to persist for many years, and the Norwegian-Swedish border consists largely today in the form of border between Bohuslän and Västergötland, which the stone monument in Kungälv is a remembrance of.
Around the year 1450 was considered Bohus to be Norway's most resilient castle, with ring walls of 3 meters thickness and which were up to 13.5 meters high. Inside the city walls, there were four length of buildings centred on a large, nearly rectangular courtyard. The entrance was in the north, not where you go in today. The medieval Bohus surface was more than 3.700 m².
In the corners and centre on the two sides were square towers, which on the west side was a forward shooting gate tower with drawbridge. The buildings on the ring wall inside contained everything from kitchen and a smithy to the chapel and dining facilities.
The large Nordic seven years war 1563 -70 led to Bohus was attacked six times in succession without being occupied by the Swedes. This at the same time, while Denmark tried to occupy the Swedish Elfsborg at Göta River estuary.
After the winter of 1564 have been rattling on the Bohus with mortars and guns but frequently no significant results had King Erik XIV send after a huge cannon that went under the name Skjegge. Cannon was, however, never get to show what it was made for, when they was to carry Skjegge over the frozen river, the ice broke and the cannon ended up on the bottom. And there it still lies today, by the small town Lödöse.
Some years after the seven year war, Bohus became heavily developed with great bastions in a star around the medieval castle heart.
The bastions were huge embankments, covered with several feet thick outer walls of gray stone to protect against gunfire.
In the inner corner they built and underground bomb safe room, so called flank ring discarded matter, to be able to shoot fire along the outer walls.
By the peace in Roskilde in year 1658 Bohus is released with subordinate counties to Sweden.
In the 1700s continued repairs, but only on the most derelict walls.
In connection with Karl XII's war against Norway abducted
most of the fortress cannons to Svinesund.
Most ancient fortifications have also been used as a state prison and Bohus is no exception.
During the Middle Ages, it was mostly political opponents "were put in the tower."
At the major expansion works at the beginning of the l600's probably used in convicts to the heavier work together with soldiers and daily work required peasants, while the construction work was done by craftsmen.
The big well in the middle of the castle yard was built of lifetime prisoners and took almost fifteen years to buil, which took place during the l600's first section. With fire and water blew itself down to the entire 22 m deep in the hard Bohus granite.
During the 1700s worked many Polish and Russian prisoners of war at Bohus under great hardships. At mid-century the prison registers included seventy-two men and five women.