What happened at the Battle of Heligoland in May 1864?

The Battle of Heligoland, which took place on May 9, 1864, was a naval engagement during the German-Danish War between Denmark and a joint Prussian-Austrian force.1

The conflict arose from the Danish naval blockade of the German North Sea coast, which had severely disrupted German shipping. Seeking to break this blockade, an Austro-Prussian squadron engaged three Danish ships off the island of Heligoland. While the Prussian ships were present, they were unable to keep pace with the action, leaving the battle primarily as a fight between the Danish and Austrian vessels.1

The Danes, commanded by Captain Edouard Suenson, successfully concentrated their fire on the Austrian flagship, Schwartzenberg, causing significant damage and starting a fire. The Austrian ship was forced to retreat into neutral British waters for safety. Although the Danish flagship Jylland suffered steering damage that prevented the Danes from intercepting the retreating force, the blockade remained intact. The engagement resulted in a tactical victory for the Danes, though it did not alter the ultimate outcome of the war, which ended in a Danish defeat.12