The fortification was built in support of Sverre Sigurdsson's struggle against his rival King Magnus Erlingsson to claim the throne of Norway.

[1][2] Defense of the city of Trondheim and the location of Sverresborg was based on three key topographical features: In 1177, Sverre Sigurdsson, who would later rule as king of Norway from 1184-1202, led the rebel Birkebeiner (Birkebeinerne) forces to Trøndelag where Sverre was hailed as king at Øretinget, the Thing (assembly) for Trøndelag.

Sverre held Trøndelag from Nidaros, which was then protected by a wooden palisades extending from the river to the fjord across the neck of the peninsula connecting the town to the mainland.

But Magnus exploited Sverre’s absence from Trøndelag when in November he raided and burned the Birkebeiner fleet located there.

During the summer of 1182, Magnus made an attempt to take Nidaros by siege, but was repulsed with grave losses when the Birkebeins launched a surprise night attack.

In the winter of 1182/1183 Sverre initiated construction of Sverresborg (one of the earliest Norwegian fortresses) to provide him a more secure and more easily defended base from which reside and operate from.

[9] In 1914 the area surrounding the ruins of King Sverre's medieval castle was appropriated for the site of the new open-air museum.

The museum had started in 1909, when a group of enthusiasts decided to gather buildings and objects characteristic of the area for purposes of preservation.

[10] In 1938, excavations were undertaken on the site and a skeleton was discovered in the filled in well, thought to date from 1197 battle recorded in the Sverris Saga.