As Kongsvinger formed a key junction point for these routes, fortifications were constructed there to protect against invasion from the east.

The Bagler faction contested with the Birkebeiners, led by the pretender King Sverre, for control during the late 12th century.

Vinger was the staging area for several minor Norwegian invasions into Sweden as this final episode of the Thirty Years' War was completed.

The most important consequence of this war was that the royal governor identified the need for fortifications at Vinger and elsewhere along the border and initiated a tax for the purpose.

Since there was great discontent, this tax burden was lifted in 1646 by Christian IV of Denmark and Norway; as a result no fortification construction was begun at that time.

Today, Øvrebyen, the old Kongsvinger uptown area around the fortress is dominated by wooden buildings from the 18th and 19th centuries, laid out in the typical right angle square plan - by architect Major General Johan Caspar von Cicignon - popular in this period.

Later, in 1814, the most bloody battle between Swedish invaders and defending Norwegian forces during the Napoleonic Wars took place at Matrand, a short distance from Kongsvinger on the Eidskog road.

[1] Aasmund Olavsson Vinje (1818–1870) was a famous Norwegian poet and journalist who wrote in his Ferdaminni fraa Sumaren 1860, "One of the finest views in the country is to stand at Kongsvinger Fortress and gaze down the Glomma."

In August 1942 a school providing four-week course in national socialist ideology opened for the Germanske SS Norge at Kongsvinger Fortress.