1923 Germany (Weimar Republic) 10 Million Marks Banknote - Post-WWI Hyperinflation Currency P# 106a Grades Select AU. In the early 1920s, post-WWI Germany saw its economy spiraling out of control. Hyperinflation started directly after the war in 1918, but truly took over the Weimar Republic from 1921 to 1923. The value of the Mark declined incredibly rapidly. 1 USD was equal to 50 German Marks at the beginning of 1920. Toward the end of 1923, 1 USD was equal to over 4,200,000,000,000 German Marks. At times, denominations of the Mark became less valuable than the paper and labor to print it almost immediately after printing. Thus, denominations of the Mark notes became incredibly large, ending up in the tens of trillions.