Which currency crisis was called Black Wednesday after Britain left the European Exchange Rate Mechanism?

Black Wednesday was the pound sterling crisis that forced Britain to withdraw from the European Exchange Rate Mechanism on September 16, 1992.

The ERM attempted to keep participating currencies within agreed exchange-rate bands before the planned introduction of the euro. Britain had joined in 1990, but economic conditions made it difficult to maintain sterling’s required value against other currencies.

Speculators, most famously George Soros’s hedge fund, built large positions against the pound. The British government raised interest rates and spent foreign-exchange reserves to defend sterling, but those measures failed. Britain suspended the pound’s ERM membership that day.

The episode is often remembered as a stock-market crash because it caused major financial-market turmoil, but its central event was a currency and exchange-rate crisis. Britain’s later economic recovery complicated the political interpretation: the government suffered a major reputational defeat, while lower interest rates after leaving the ERM helped economic activity.