On 9 May 1864, in the North Sea a few miles off the island of Heligoland, a Danish squadron of two frigates and a corvette under Commander Edouard Suenson fought an Austrian and Prussian squadron led by Captain Wilhelm von Tegetthoff. The Austrian flagship Schwarzenberg caught fire, and Tegetthoff broke off the fight and took shelter in the neutral waters of the island, which was then British. Denmark celebrated a victory, but it could not change the outcome of a war it was losing on land.
A blockade in the North Sea
Prussia and Austria declared war on Denmark on 1 February 1864 over the duchies of Schleswig and Holstein. Denmark's navy answered with a blockade of ports in the duchies and in Prussia, and since the Prussian navy was too weak to break it, Austria sent ships to help its ally. Tegetthoff sailed north with the frigates Schwarzenberg and Radetzky to break the blockade together with three smaller Prussian vessels, and Orbán adds the Austrian gunboat Seehund.1 › Battle of Jasmund, 1864
Suenson commanded the frigates Niels Juel and Jylland and the corvette Heimdal. The Danish encyclopedia Lex, in an entry by the naval historian Ole Ventegodt, judges the two forces roughly equal. Ventegodt names the Prussian ships as the paddle steamer Adler and the gunboats Basilisk and Blitz.2
The fight off Heligoland
Ventegodt places the fight about ten nautical miles southeast of Heligoland, an island that then belonged to Britain. Two Danish sailors who fought aboard Jylland describe Suenson hailing his crews before the battle and calling on them to do their duty as their comrades had done on land. One of them, Anders Jensen Lønborg, wrote that the squadron had furled its sails at seven in the morning and gone into action under steam.3
The fight was a gunnery duel at close range. Lønborg describes a shell that came through Jylland's side between two guns, burst, and killed or wounded nearly the whole crew of one of them; he was wounded himself. The Prussian ships never took an active part. On the Austrian side, the foretop of Schwarzenberg was set on fire by Danish shells, and Tegetthoff broke off the action and ran for the neutral British waters under Heligoland to make repairs.4
Victory or draw
The two sides told the result differently. Danish sources call it a victory in which the Danish squadron put its enemies to flight. The Austrian historian Gábor Orbán, writing in Militär Aktuell, calls the battle inconclusive after heavy firing on both sides, but notes that the Danes lifted their blockade afterward. The losses also became a matter of story telling. Lønborg claimed that Schwarzenberg alone had 174 dead; the editors of the Danish history portal Danmarkshistorien point out that the official figure was 32. Ventegodt writes that the Danish squadron went to Kristiansand in Norway, where 14 of its dead were buried. Lønborg, who was there, counted 15 coffins, 12 from Jylland and 3 from Niels Juel.5
In Copenhagen Suenson was welcomed as a hero. Ventegodt adds that he was later criticized, with some justice, for not waiting until the Austrians had to leave the shelter of Heligoland and forcing a real decision. By the time the squadron reached Copenhagen on Whit Sunday a ceasefire was in force. The victory at sea did not change the course of the war, which Denmark lost.6
The lesson Tegetthoff took to Lissa
For Tegetthoff the fight was a lesson. According to Orbán, he saw that the smoothbore guns of his ships had little effect against the rifled guns of the Danes, and concluded that Austrian warships, being poorly armed, should drive straight at the enemy instead of wasting themselves in gunnery duels. Two years later, at Lissa in the Adriatic, he did exactly that: his fleet rammed and sank the Italian flagship Re d'Italia and won the battle. That victory is told on our page for 20 July.7
Also on this day
- 1915: Battle of Arras. On the Western Front, Polish volunteers of the French Foreign Legion, the Bayonne Legion, attacked German positions on the Vimy heights north of Arras.
