50 000 000 000 Mark Thüringische Staatsbank

Thüringia's state bank was one of dozens of regional German institutions authorized to issue emergency currency during the hyperinflationary collapse of 1923, when the Reichsbank simply could not print fast enough to keep pace with depreciation. By the time 50-billion-mark denominations became necessary — late October and November 1923 — a single US dollar was worth roughly 4.2 trillion marks. Notes of this face value had a practical lifespan measured in days before they were economically worthless.

The watermark security feature was largely symbolic at this stage. Counterfeiting was almost pointless when the cost of forgery exceeded the note's purchasing power before the ink dried.