Although the 23rd April 1848 is usually associated with the Battle of Schleswig another action was fought on the same day at Mysunde which dramatically influenced its outcome. As can be seen from the accompanying map the village of Mysunde was (and is), located on a small strait of the Slien Fjord where it is only 125 m (135 yards) wide.

Mysunde's significance lay in the fact that it boasted the only cable ferry on the Slien making it the only place where it was possible to get cavalry and artillery across the Fjord. Consequently on the day of the battle of Schleswig, its occupation protected the left flank of the Danish positions.

The Danish garrison at Mysunde, under the command of Lieutenant Colonel Haxthausen, consisted of:

• Three companies of the 5th Battalion. Commanded by Nielsen, Harboe, Brun.
• Two 12 pounds howitzers from Dinesen's Battery under command of Lieutenant Joergensen.
• 40 Dragoons under command of Captain (Ritmester) Flindt.
• One engineer section.
  

A picket line drawn from these units had been established to the south stretching from Holm in the west, through Kosel, to Snap Moelle (Snap Mills) in the east. On the evening of April 22nd rumours placed 3-4.000 Schleswig-Holstein troops just south of Osterby. To confirm this patrols were send out. Further patrols were sent out on the following morning and one of these consisting of 40 infantry and 16 dragoons encountered the enemy advancing from the west.

Finding its way to back to Mysunde blocked by the advancing Schleswig-Holsteiners, whose artillery had already occupied Kosel, the patrol went into Erkenfoerde together with twelve infantry and ten dragoons from the picket line who had also been cut off.

The approaching Schleswig-Holstein force, which was commanded by Major Zastrov, was composed of:

• five line infantry companies
• a half squadron of dragoons
• four three pound cannon
• In addition there were four Freikorps units

Wasner's Freikorps
Krogh's Freikorps
Ranzaus' Freikorps (these three units totalled 1,200 men)
Major Von den Tann's Freikorps (500)

Major Von den Tann's unit stayed at Store Wittensoe. The other three Friekorps under Captain Aldosser moved to Stubbe in order to cross Slien while the forces commanded by Zastrow approached Mysunde to take the crossing. Just how this was to be achieved is unclear as they lacked pontoons, boats and any other bridging equipment necessary to make a crossing possible. In the face of their advance the Danish troops withdrew as quickly as possible to the north side of the Slien.

At about 8.30 am the Schleswig - Holstein troops occupied Mysunde and immediately began to exchange fire with the Danish troops on the opposite bank. Despite lasting until evening this firefight resulted in very few casualties primarily because the smoothbore weapons used by the majority of the men engaged had insufficient range. Losses amounted to only five wounded for the Danes and seven wounded and one dead for the Schleswig-Holsteiners.

The combat might have ended in this way except for the presence of 60 Friekorps troops on the Danish side of the Slien. On the previous evening these men from Zastrow's command had managed to cross the Slien with the aid of local fishermen and now made their presence felt both here at Mysunde and in the battle of Schleswig being fought further to the west.

Between six and seven o'clock in the evening these troops ambushed a number of Danish supply wagons and then erected barricades in the town of Brodersby. Upon learning that enemy troops were threatening his rear and not knowing their numbers (he estimated them to number 1,200 !!), Haxthausen choose to withdraw thus leaving the crossing in the hands of the Schleswig Holstieners.

However this was not the most serious consequence of their presence. Rumours of their existence had reached the Danish army fighting at Schleswig. As they appeared to be in a position to threaten the Danish left flank position in Gottorp Castle the Royal Guards, who occupied it, were hastily withdrawn. Unfortunately this occurred at the moment when the Danes were preparing to launch a counterattack which may well have resulted in their victory. Although the mistake was quickly realised and corrected, the moment for the counterattack had passed and the battle ended in a Danish defeat.