After the battle, SMS Schleswig-Holstein faced a period of much-needed repairs before being put back out to sea. She entered combat waters once more in early 1917 and served in the role until May 2nd of that year, now facing decommissioning from active service. In August of 1917, she was rearranged as an "accommodation ship" for service personnel and was based at Bremerhaven before finally being relocated to Kiel in 1918 where she served out her tenure until the end of the war in November. Of the five ships in her class, only four survived the whole of the war and only three of these were allowed to continue service with the German Navy under the 1919 Treaty of Versailles. SMS Schleswig-Holstein was joined by SMS Schlesien and SMS Hannover while the SMS Deutschland was selected for the scrapman's torch in 1922. A modernization program was then enacted throughout the 1920s that saw the SMS Schleswig-Holstein upgraded and furthermore promoted to flagship of the rebuilding German Navy. She held that post from 1926 to 1935.
By 1939, an armament refit had brought about some changes to the decks of the SMS Schleswig-Holstein in preparation for Hitler's world war with the rest of Europe. Her 4 x 11" SK L/40 main guns remained intact but she lost all of her casemated 6.7" cannons. Only 2 x 3.5" cannons remained of the original twenty-two installed though these were no longer in limited casemates and 4 x 1.5" cannons were added. A further 22 x 20mm anti-aircraft cannons were fitted for a lethal network air defense system and her six 18" torpedo tubes were removed in full. Despite their inherently outdated designs, the remaining Deutschland-class warships were still of some value based on armament and speed. As such, they made for serviceable bombardment platforms and would be utilized as such in World War 2. The SMS Schleswig-Holstein was credited with firing the first salvo that officially began World War 2 - this occurring on September 1st, 1939 against Polish fortifications near Danzig off of the Baltic Sea (today known as Gdansk, Poland).
With Captain Gustav Kleikamp in command of SMS Schleswig Holstein, she and her sister ship, SMS Schlesien, were on a planned visit to the nation of Poland. This subterfuge was meant to honor German sailors killed on the cruiser Magdeburg back in World War 1 and were buried in Danzig in 1914. The Magdeburg had run aground near the Odensholm lighthouse in the Baltic Sea. Efforts to refloat her ultimately failed and the Russian cruisers Bogatyr and Pallada appeared and utterly destroyed her, killing off most of her crew in the process.
Schleswig Holstein and her small flotilla had anchored in Danzig harbour at the mouth of the River Vistula. At 4.30am on September 1st, 1939, she weighed anchor and moved down the canal, taking up a position opposite the Polish fort at Westerplatte. SMS Schlesien and the accompanying gunboats remained to protected the mouth of the harbor. The plan of German High Command proposed the SMS Schleswig Holstein with her 11-inch guns at point blank range against the forts while Captain Kleikamp, at 4.47am, gave the formal order to open fire on the Westerplatte in the name of Adolf Hitler. Germany's first shot fired by the SMS Schleswig Holstein of World War 2 in Europe was exactly 20 years, 9 months, 19 days and 18 hours after the last recorded shot was fired in World War 1. World War 2 in Europe had officially begun.
The bombardment of the fort was joined by Junkers Ju 87 "Stuka" dive bombers of the German Luftwaffe and the few Polish garrison defenders were additionally attacked by larger numbers of German ground troops. The battle lasted for seven days before the Polish commander surrendered (though the fort was never truly taken by the German troops). In the first few weeks of the ensuing World War, the SMS Schleswig-Holstein and the SMS Schlesien bombarded other Polish positions in Gdynia, Kepa Oksywska, and the Hel Peninsula.
Death of the SMS Schleswig-Holstein
The remaining Deutschland-class battleships were returned to training duty following the German occupation of Norway in 1940. SMS Schleswig-Holstein became an anti-aircraft platform in 1944 stationed at Gdynia to protect the port from enemy air attacks. There she would berth until the end of her tenure in the war for, being a stationary target now, she was attacked by aircraft of the Royal Air Force on December 18th, 1944, that resulted in the death of twenty-eight of her crew. The RAF attacked once again and scored several direct hits with aerial bombs, leaving her a burning wreck on the water. She finally sank in 39 feet of water near the port on March 21st, 1945. The war in Europe ended in May.
After World War 2, she was raised by the Soviet Union and towed to the Russian port of Tallinn where she was believed to be renamed to "Borodino". The Soviet Navy scuttled Borodino in shallow water near Osmussaar Island in the Baltic Sea sometime in 1948 and she was used as a target ship until 1964. Decades later, the remains of the ship came under the protection of the Estonian National Heritage Board as a "historic shipwreck" which has been her title since 2006.
The battleship Schleswig Holstein served Germany in both world wars and was the single instrument used to begin the Second World War. A conflict, by some reports, that claimed the lives of over 60 million people. It is doubtful that this number reflects all the peoples in all of the far corners of the world where records were, at best, dubious. Nevertheless, the SMS Schleswig-Holstein earned her due respect and legacy - even though she finished her career not in the service that her builders originally intended.