50 Pfennigs

Friedrichstadt — founded in 1621 by Dutch Remonstrant refugees and still visibly Dutch in its canal layout — issued this square note during the notgeld period that followed Germany's post-WWI economic dislocation. The 45 x 45 mm format is genuinely unusual; square notgeld are among the less common physical variants from this era, and the town's print runs were small enough that attrition has done real work on surviving numbers.

Schleswig-Holstein's political status was itself unsettled in 1920 — the province was subject to a plebiscite that year determining the Danish-German border, which adds an odd administrative wrinkle to any local currency issued at that exact moment.