Admiral as a rank first appeared in Germany in the 19th century and was expanded in the early 20th century as part of a build-up and mobilization in preparation for the First World War. The rank again saw a resurgence during the Second World War. There were many famous German Admirals during these formative years of German naval power, among them Otto von Diederichs, Gustav von Senden-Bibran, Georg Alexander von Müller, August von Heeringen, Alfred von Tirpitz and (later) Karl Dönitz.