ECU European union

The ECU was never legal tender — it existed as a basket currency, a weighted average of member-state currencies used for accounting, bond issuance, and interbank settlement. These pieces, struck by various European mints throughout the late 1980s and 1990s, are commemorative medals issued by private and semi-official bodies capitalizing on European unity sentiment, not official coinage of any sovereign or supranational authority. The Maastricht Treaty of 1992 had already sealed the ECU's fate, scheduling its replacement by the euro at a fixed 1:1 rate on January 1, 1999.