SMS Seydlitz was a German battlecruiser (according to the German classification from the beginning of the 20th century - a great cruiser) from the First World War. The keel for this unit was laid in 1911, the launch took place in March 1912, and entry into service in Kaiserliche Marine - in 1913. The length of the ship was 200.6 meters and a width of 28.5 meters. Full displacement reached approx. 28,600 tons, and maximum speed - to approx. 26-27 knots. The deck armament, at the time of launch, consisted of 10 280 mm guns placed in five turrets of two guns each, 12 guns 150 mm and 12 guns 88 mm. SMS Seydlitz was one of its class. Its design was based on the earlier Moltke-class battlecruisers, and the new ship was significantly enlarged compared to its predecessors in order to give the vessel the best seaworthiness and high damage resistance. Interestingly, the armament is exactly the same compared to the Moltke-class units! In general, SMS Seydlitz can be considered a successful vessel with relatively strong armament, good top speed and very high seaworthiness. The cruiser took part in many battles during World War I, including: in 1915 he took part in the Dogger Bank battle, and in 1916 he fought in the Battle of Jutland, where he was seriously damaged but returned safely to the port. For a short period of time, in 1915, he was also active in the Baltic Sea. SMS Seydlitz, after the end of World War I, was interned at the British base at Scapa Flow, where he was sunk by his own crew on June 21, 1919. A few years later, it was excavated by the British and scrapped in 1928-1930.