100 Francs

The Banque Internationale à Luxembourg was a private commercial bank, not a central bank — which makes this series unusual by European standards of the period. Luxembourg had no central bank until 1998, and private institutions were authorized to issue notes to fill that gap. The BIL, founded in 1856, was the dominant force in this arrangement for decades.

Pick numbers 9 through 11 reflect signature varieties across the seventeen-year span rather than fundamental design changes — a long run for a private-issue series operating through the Depression years and right up to the German occupation in May 1940, which effectively ended circulation.