5 Mark

Marienburg — now Malbork, Poland — was the seat of the Teutonic Knights' grand masters and, by 1918, a mid-sized Westprussia garrison town issuing its own emergency paper alongside hundreds of other German municipalities. This Notgeld note appeared as the imperial monetary system buckled under wartime strain, with the Reichsbank unable to keep small-denomination coinage in circulation. Local magistrates were legally permitted to fill that gap, and Marienburg did so with a 5 Mark piece bearing nothing more sophisticated than an official municipal seal as its sole check against forgery.

The seal alone made counterfeiting awkward but hardly impossible. Worth remembering when examining any example.