20 000 000 Mark Birkenfelder Landesbank

The Birkenfelder Landesbank was a regional institution serving the former Principality of Birkenfeld, a Prussian exclave embedded within the Grand Duchy of Oldenburg — a geographical anomaly that persisted into the Weimar period. By mid-1923, German hyperinflation had reached the point where municipal and regional banks were authorised under emergency notgeld provisions to issue their own high-denomination notes to keep commerce functional. Twenty million marks was not an absurd sum by August 1923 standards; within weeks it would be.

The watermarked paper distinguishes this from the purely utilitarian emergency issues of smaller municipalities that used whatever stock was available.