The failed Swedish assault on Copenhagen in 1659 preserved Danish independence and marked a turning point in the Second Northern War.
Key Facts
- Date of assault
- 11 February 1659
- Swedish arrival on Zealand
- 7 August 1658
- Siege start at Copenhagen
- 11 August 1658
- Treaty ending the siege
- Treaty of Copenhagen, 27 May 1660
- Swedish assault outcome
- Repelled with heavy Swedish losses
By the Numbers
Location
Cause → Event → Consequence
Following the Swedish invasion of Zealand on 7 August 1658, Charles X Gustav sought to conquer Denmark by capturing Copenhagen. Rather than launching an immediate attack, Swedish forces settled into a prolonged siege beginning 11 August 1658, waiting for an opportune moment to storm the city.
On 11 February 1659, Swedish forces under Charles X Gustav launched a full assault on Copenhagen. The attack was repelled by the defending Dano-Dutch garrison, resulting in heavy Swedish casualties. Historians attribute the failure primarily to poor planning and rash decision-making by the Swedish king, who sent his troops against well-prepared defences.
Although the failed assault weakened Swedish forces, the siege of Copenhagen continued for approximately another year. It was not formally ended until the signing of the Treaty of Copenhagen on 27 May 1660, which concluded the Second Northern War and preserved Danish sovereignty.
Belligerents & Mobilization Analysis
Side A
1 belligerent
Charles X Gustav.
Side B
1 belligerent