2500 Francs Congress of Gniezno

The Congress of Gniezno in 1000 AD was a meeting between Holy Roman Emperor Otto III and Bolesław I of Poland, held at the tomb of Saint Adalbert. Otto's gesture of placing his imperial diadem on Bolesław's head — and what that act did or did not signify about Polish sovereignty — has been debated by historians for a millennium. The congress is considered a founding moment of the Polish state's international recognition.

That a Central African franc-denominated coin commemorates a medieval Polish event reflects the well-established practice of BEAC-affiliated mints producing collector issues with no connection to the issuing territory's history.