The
mark was the currency of
Germany until the implementation of the
Rentenmark in
1924. It is probably most famous for its ludicrous levels of
inflation during the
Weimar Republic period following the end of
World War I. For example, witness the average price of a loaf of
rye bread:
1914: 32 pfennigs
1919: 80 pfennigs
1920: 2.37 marks
1921: 3.90 marks
Dec. 1922: 163.15 marks
Jan. 1923: 250 marks
July 1923: 3,465 marks
Dec. 1923: 399 billion marks
(Data from Saishin-sekaishi-zuhyo 6th ed., Dai-Ichi Gakuikusha, 2000)
Obviously, these hyper-inflated prices made the bills more useful as toilet paper than currency: anyone wanting to go shopping would have to bring a wheelbarrow full of cash with them. By the time that people started buying 400 billion mark loaves of bread, the government decided to issue new marks worth 1 trillion old marks; hence, the Rentenmark, which was the currency until the rise of the Nazis.
There's a much more detailed discussion of this at Hyperinflation in Weimar Germany.
At any rate, the ensuing Great Depression that screwed up all of the world's major economies didn't help things much either. And this, children, is part of the story behind how we got Adolf Hitler.