The Kaiser class were five dreadnought battleships that were built for the German Kaiserliche Marine in the 1910s: Kaiser, Friedrich der Grosse, Kaiserin, Prinzregent Luitpold, and König Albert. They entered service shortly before World War I, and saw significant combat during the conflict. The Kaiser-class ships introduced several technological improvements to German battleship design, including steam turbines for propulsion and a more efficient superfiring arrangement for some of their main battery guns. They were also faster and more heavily armored than their predecessors of the Nassau and Helgoland classes. Carrying a primary armament of ten 30.5 cm (12 in) guns, they were less heavily armed compared to their British counterparts.