The battle came about over British fears that the powerful Danish fleet would ally with France, and a breakdown in diplomatic communications on both sides.

The Danes agreed to the British terms upon hearing news of the assassination of Emperor Paul I of Russia, as his death meant the end of the Russian-led League of Armed Neutrality of which Denmark was a member.

The Russian tsar, Paul, having been a British ally, arranged a League of Armed Neutrality comprising Denmark, Sweden, Prussia, and Russia, to enforce free trade with France.

The British needed to act before the Baltic Sea thawed and released the Russian fleet from its bases at Kronstadt and Reval (now Tallinn).

[6] This prompted the Earl of St Vincent (First Lord of the Admiralty) to send a private note, which resulted in the fleet sailing from Yarmouth on 12 March.

[7] Orders were sent to Parker to go to Copenhagen and detach Denmark from the league by "amicable arrangement or by actual hostilities", to be followed by "an immediate and vigorous attack" on the Russians at Reval and then Kronstadt.

[clarification needed] Although the Admiralty had instructed Parker to frustrate the league, by force if necessary, he was a naturally cautious person and moved slowly.

[9] Attacking the Danish fleet would have been difficult as Parker's delay in sailing had allowed the Danes to prepare their positions well.

North of the fort, in the entrance to Copenhagen harbour, were two ships-of-the-line, a large frigate, and two brigs, all rigged for sea, and two more hulks.

Batteries covered the water between the Danish line and the shore, and further out to sea a large shoal, the Middle Ground, constricted the channel.

The British had no reliable charts or pilots, so Captain Thomas Hardy spent most of the night of 31 March taking soundings in the channel up to the Danish line.

[citation needed] Parker himself stayed to the north-east of the battle with the heavier ships – whose deeper drafts did not allow them to safely enter the channel – screening Nelson from possible external interference and moving towards Copenhagen to engage the northern defences.

On 30 March, Nelson, and his second-in-command, Rear Admiral Thomas Graves, accompanied by Captain Domett and the commanding officer of the troops, Lieutenant Colonel William Stewart, sailed in the hired lugger Lark to reconnoitre the Danish defences at Copenhagen.

The northern Danish ships, which were rigged and manned, did not enter the battle but remained on station as reserve units, even though the wind direction forced Parker's squadron to approach only slowly.

The guns of the dozen southernmost Danish ships had started to fall silent owing to the damage they had sustained, and the fighting moved northward.

[note 5] Perhaps because of inexperienced crews, several Danish ships fired on British boats sent out to them after their officers had signalled their surrender.

He sent it with a Danish-speaking officer, Captain Sir Frederick Thesiger, under a flag of truce to the Danish-Norwegian regent, Crown Prince Frederik, who had been watching the battle from the ramparts of the Citadel.

[16] The note read: To the Brothers of Englishmen, the Danes Lord Nelson has directions to spare Denmark when she is no longer resisting, but if firing is continued on the part of Denmark, Lord Nelson will be obliged to set on fire the floating batteries he has taken, without having the power of saving the brave Danes who have defended them.

All action ceased when Crown Prince Frederick sent his Adjutant General, Hans Lindholm (a Danish member of parliament), asking for the reason for Nelson's letter.

When he could not clearly communicate verbally, Lindholm was asked to put his message in written English, which he did, but being given a dull quill, he joked: If your guns are not better pointed than your pens, then you will make little impression on Copenhagen.In reply, Nelson wrote a note: Lord Nelson's object in sending the Flag of Truce was humanity; he therefore consents that hostilities shall cease, and that the wounded Danes may be taken on shore.

[citation needed] The official report by Olfert Fischer estimated the Danish-Norwegian casualties to be between 1,600 and 1,800 captured, killed or wounded.

Hurried apologies followed (the British fleet now occupied positions that would allow the bombardment of Copenhagen) and agreement was reached and signed the next day.

[25] Parker refused to sail into the eastern Baltic and instead returned to Copenhagen, where he found that news of his lack of vigour had reached London.

Nelson sailed eastwards again and, leaving six ships-of-the-line at Karlskrona, he arrived at Reval on 14 May to find that the ice had melted and the Russian fleet had departed for Kronstadt.

The death of Tsar Paul of Russia changed the diplomatic scene and reduced the political importance of the battle, and material losses in the battle were of little importance to the fighting strength of either navy (the Danish side had taken great care to spare its first-class ships), it did however demonstrate that British determination to ensure continued naval superiority in the war against France was supreme.