100 ECU Miguel de Cervantes

The ECU — European Currency Unit — was never physical legal tender but existed as a basket currency used in EU accounting and exchange rate mechanisms from 1979 until it was replaced by the euro in 1999. Spain's Royal Mint issued a series of collector ECU denominations through the early-to-mid 1990s, largely as a political gesture toward European integration during a period when Spain was still consolidating its post-Franco membership in the European Community, having only joined in 1986.

Cervantes died in Madrid on April 22, 1616 — one day before Shakespeare, a coincidence that has fueled centuries of literary mythology despite the two men sharing no known contact.