The short answer is Germany got into the game long after most of the rest of Europe. There were numerous Germanic speaking states/territories/regions in the 19th century. These different regions were not unified until Bismarck in 1870 and 1876. Until that point they were regularly at war or in conflict with each other. Prussia, Bavaria, Hanover, and Saxony are among the largest German states that were united under Bismarck (with Austria being left out). While many European countries or speaking regions were in conflict with each other throughout history, the German's "unified" later than other regions.