Loss of the cruiser SMS Magdeburg

On 26 August 1914 the German light cruiser SMS Magdeburg ran onto rocks in fog off the islet of Odensholm, today’s Estonian Osmussaar, at the entrance to the Gulf of Finland. The ship could not be saved, and Russian cruisers that arrived in the morning shelled her and forced the rest of the crew to surrender. The loss of the cruiser in itself was a minor episode of the war in the Baltic. Its consequences, however, proved enormous, because the Russians found German codebooks at the wreck, which later reached the British.

Not off the Åland Islands

A British chronology of events from those years describes this as a naval engagement “off the Åland Islands” in which a Russian squadron destroyed the Magdeburg. Both elements are inaccurate. The Åland Islands lie at the entrance to the Gulf of Bothnia, between Sweden and Finland, while Odensholm lies roughly 200 kilometres further east, off the north-western coast of Estonia, near the port of Paldiski, then called Baltic Port. Nor was the ship lost in battle: she was undone by fog and a navigational error, and the Russians merely finished off an already immobilised wreck.

The sortie to the Gulf of Finland

The Magdeburg entered service in 1912. She was a modern cruiser armed with 12 105 mm guns and capable of carrying mines. Before the war she served as a training ship, and from the first days of August she operated in the eastern Baltic: on 2 August, together with the cruiser Augsburg, she shelled the Russian port of Libau, and later operated in the Gulf of Riga.

On 25 August the Magdeburg and the Augsburg, escorted by torpedo boats, set out towards the Gulf of Finland. The squadron was commanded by Rear Admiral Ehler Behring. The Germans were to reconnoitre the entrance to the gulf in search of Russian scouting vessels and to lay mines there. In the evening and during the night the sea was shrouded in thick fog.

On the rocks of Odensholm

Shortly after midnight, at about 1 a.m. on 26 August, the Magdeburg, steaming at about 15 knots, ran onto rocks near the lighthouse on Odensholm. The damage to her bottom was serious. For several hours the crew tried to get the ship off: ammunition, anchor chains and other heavy equipment were thrown overboard, but the cruiser would not budge. The torpedo boat V 26 came to help and tried to take her in tow, also without success.

The ship’s commander, Lieutenant Commander Richard Habenicht, decided to blow up the cruiser so that she would not fall into Russian hands, and began transferring the crew to V 26. Meanwhile Russian observers on the island alerted the command at Baltic Port. The cruisers Bogatyr and Pallada put out and at about 9 a.m. opened fire. The Magdeburg replied as long as she could. The demolition charges went off prematurely, destroying the forward part of the ship and killing some of the sailors who were still on board. The torpedo boat V 26, herself hit, sailed away with the rescued men.

More than a dozen crew members were killed, and some were listed as missing. Sources give different figures: usually 15–17 killed are mentioned. Most of the crew were rescued by V 26. Some 50–60 men, including Commander Habenicht, were taken prisoner by the Russians; the commander returned from captivity only in 1918.

A prize that changed the war at sea

What proved most important was what the Russians found on and around the wreck. The Germans had not managed to destroy all the secret documents. Russian sailors and divers found on board and in the shallow water alongside copies of the Kaiserliche Marine codebook, known as the SKM (Signalbuch der Kaiserlichen Marine), together with the current cipher key, as well as charts and the logbook. Winston Churchill’s memoirs contain a striking story that the book was found clasped in the arms of a drowned German signaller. Historians treat it rather as a legend.

The Russians acted generously: they handed one copy of the book to their ally, Great Britain. It was delivered by Russian officers, and on 13 October 1914 the codebook reached the hands of the First Lord of the Admiralty, Winston Churchill. It was taken over by the newly created codebreaking unit of British naval intelligence, known as Room 40.

The codebook from the Magdeburg, supplemented by other captures from those months, allowed the British to read much of the German radio traffic. The Admiralty often knew in advance when the German fleet was putting to sea. This led to the Battle of Dogger Bank in January 1915, and in May 1916 the British Grand Fleet put to sea even before the Germans, which led to the Battle of Jutland. For a long time the Germans did not realise how much their enemy knew.

A Polish connection

The bodies of more than a dozen sailors from the Magdeburg and V 26 were buried in a mass grave in what is today the Garrison Cemetery in Gdańsk (PL). In the days of the Free City, German anniversary ceremonies were held there every year. On the pretext of taking part in such a ceremony, on 25 August 1939 the battleship Schleswig-Holstein entered the port of Danzig, and on 1 September 1939 she opened fire on the Polish depot at Westerplatte. The monument on the grave of the Magdeburg’s sailors still stands in the cemetery today.