20 Francs

Pick 42 places this note at the very beginning of the Banque Nationale de Belgique's existence — the bank was only established by royal decree in 1850, the same year this note was issued. It was conceived partly to stabilize a country still economically rattled by the 1848 revolutionary upheavals that had swept through continental Europe and interrupted credit flows across Belgium's industrial centers.

Early BNB issues of this period are rarely encountered in any condition. The redemption rate for nineteenth-century Belgian paper was high, and few private holders thought to preserve them.