The Battle of Copenhagen occurred when a British Royal Navy squadron, under the command of Vice-Admiral Horatio Nelson, engaged the Dano-Norwegian Navy on April 2, 1801. The British forces sought to neutralize threats posed by Denmark’s recent alliance with France, part of the broader context of the French Revolutionary Wars. The Dano-Norwegian fleet, largely made up of inexperienced volunteers and hastily assembled ships, faced the well-trained and seasoned maritime forces of Britain. The battle took place in the waters surrounding Copenhagen, specifically off the coast of Zealand, amidst a backdrop of growing tensions over trade and naval supremacy in the Baltic Sea.

The battle began early in the morning with intense cannon fire exchanged between the two sides. Vice-Admiral Nelson employed aggressive tactics, including a notable maneuver where he signaled to his fleet to disregard orders and engage the enemy directly, leading to significant British victories despite incurring heavy losses. The Danish defensive fortifications and the bravery of the local militia were tested, resulting in a fierce but ultimately costly struggle for both sides. By the end of the day, the Royal Navy emerged victorious, effectively forcing Denmark to exit the Second League of Armed Neutrality, which had aimed to protect neutral shipping rights against British naval blockades.

This clash was not just a battle of fleets, but a tactical showcase that highlighted the evolving nature of naval warfare during this period. The impact of Nelson's decisions at Copenhagen would resonate beyond the scope of the immediate engagement, and it solidified Britain's dominance in the North Sea and Baltic regions for the subsequent years of conflict.