The Iron Cross
The Iron Cross is probably one of the most distinctive military decorations that there has ever been. Beyond just a commendation it also became part of the identity of the German army in the past and into the present.
Its design can be traced back to the Crusades when the King of Jerusalem gave the Teutonic Order permission to combine their solid black cross to the silver Cross of Jerusalem. The first award as a military decoration goes back to 1813 and the Napoleonic Wars. The Prussian King decided that it would best symbolize courage and strength. The decoration would be used again during the Franco-Prussian War, World War I and World War II.
As a symbol of the German Army it was used during World War I and retired at the end of the war. Only to be brought to the fore again by the Nazis in 1939. Sometimes even adorned with the swastika. After the war, it fell out of favor but was reinstated in 1956 by the West Germans. After reunification, it remains the symbol of the German Army today in various forms.
Interestingly enough, the Iron Cross citation was never revived in Germany post WWII. Though they did reissue the awards won during the war without the Nazi symbols attached to them. There has been somewhat of a movement to reinstate the Iron Cross award. In the meantime, though a new award has been put in place at the same level, The Cross of Honor for Bravery. Which is more reminiscent in design to an older Prussian medal.