Assault on Copenhagen (1659)

Assault on Copenhagen
Part of Second Northern War (Dano-Swedish War (1658-1660))
The assault of Copenhagen
The assault of Copenhagen
Date11 February 1659
Copenhagen, Denmark
ResultDanish and Dutch victory
Flag of Denmark.svg Denmark-Norway
 Dutch Republic
Flag of Sweden.svg Sweden
Commanders and leaders
Frederick IIIKarl X Gustav
Otto Stenbock
Around 10,000 Danish soldiers and armed citizens of Copenhagen, including approximately 2000 Dutch troops, plus 343 guns of various caliberAround 10,000 Swedish soldiers
Casualties and losses
14 dead and woundedAround 1,700 dead and wounded

The assault on Copenhagen on 11 February 1659 was a major battle during the Second Northern War, taking place during the siege of Copenhagen by the Swedish army.


During the Northern Wars, the Swedish army under Charles X Gustav of Sweden, after invading the Danish mainland of Jutland, swiftly crossed the frozen straits and occupied most of the Danish island of Zealand, with the invasion beginning on February 11, 1658. This forced the Danes to sue for peace. A preliminary treaty, the Treaty of Taastrup, was signed on February 18, 1658 with the final treaty, the Treaty of Roskilde, signed on February 26, 1658, granting Sweden major territorial gains.

The Swedish king, however, was not content with his stunning victory, and at the Privy Council held at Gottorp on July 7, Charles X Gustav resolved to wipe his inconvenient rival from the map of Europe. Without any warning, in defiance of international treaty, he ordered his troops to attack Denmark-Norway a second time.

The Swedish armies had never left Denmark after the peace and already occupied all of Denmark apart from the capital, Copenhagen. After a failed assault, Copenhagen was put under siege in the hope of breaking the defense by starvation. In October 1658 however a Dutch relief fleet under Lieutenant-Admiral Jacob van Wassenaer Obdam defeated the Swedish fleet in the Battle of the Sound and lifted the sea blockade so that supplies and an auxiliary army could reach the capital. The Dutch were an ally of Denmark from the Anglo-Dutch Wars and were afraid that Swedish control of the Baltic would ruin their profitable trade in this area.