50 000 Dobras

The 50,000 Dobra denomination was introduced as the top of the Banco Central's range at a point when cumulative inflation had made smaller notes practically worthless for any significant transaction. São Tomé and Príncipe's post-independence economy was heavily dependent on cocoa export revenues and foreign aid, and the dobra had been devalued repeatedly through the 1980s and 1990s before a formal stabilization agreement pegged it to the Portuguese escudo — and later to the euro — in 1997.

Thomas De La Rue's security specification for this series is notably minimal: watermark only, with no metallic thread reported for P#68. That's a thin barrier against counterfeiting for a high-denomination note, though the archipelago's small population and limited cash economy made sophisticated forgery largely impractical.