100 Pesetas - Juan Carlos I National Library

The 1996 Spanish commemorative series marking the National Library's anniversary was issued the same year Spain was deep in preparations for Economic and Monetary Union — a period when peseta-denominated coins were being produced with an implicit expiration date, as the euro's 2002 arrival was already legislated. The National Library itself was founded by royal decree of Philip V in 1711, originally as the Biblioteca Pública de Su Majestad, drawing heavily on books seized following the War of the Spanish Succession.

Aluminium bronze of this specific alloy was adopted by the Real Casa de la Moneda for the 100 peseta denomination partly for its resistance to corrosion in circulation — a practical concern given the coin's heavy everyday use throughout the 1990s.