The assault on Copenhagen represented a critical clash between Swedish forces and the Danish defenders during the Northern Wars that raged across Scandinavia in the 17th century. In early 1659, the Swedish King Charles X Gustav sought to expand his territory and influence by capturing the Danish capital. The strategic importance of Copenhagen as a gateway for naval dominance and trade motivated the Swedish troops, composed of about 13,000 men, to initiate the siege. The Danish forces, although fewer in number, were well-prepared and fortified within the city walls, determined to protect their homeland.

As the Swedish forces advanced, they were met with staunch resistance from the Danish defenders, led by notable commanders such as Crown Prince Frederik. The intense fighting over several weeks included artillery bombardments and close-quarters engagements, with both sides suffering heavy losses. However, a combination of Danish courage, strategic fortifications, and possibly underestimations by the Swedish generals led to a decisive Danish victory.

By the end of the confrontation, the Swedish forced retreated in disarray, leaving many of their casualties behind. This failed assault significantly weakened Swedish ambitions in the region and reinforced the Danish resolve to maintain their sovereignty. The incident not only contributed to the military reputation of the Danish forces but also shifted the balance of power in Scandinavia temporarily in favor of Denmark, influencing subsequent treaties and negotiations to conclude the ongoing wars. Overall, the resilience demonstrated by the Danes on that fateful day in Copenhagen continued to be a symbol of national pride for generations to come.