The 1992 currency-market crisis that forced the United Kingdom to leave the European Exchange Rate Mechanism was called Black Wednesday.
Black Wednesday occurred on September 16, 1992, when intense selling pressure targeted the pound sterling. The United Kingdom tried to defend the pound’s required exchange-rate band through interest-rate increases and foreign-exchange intervention, but those measures did not hold.
The government withdrew sterling from the Exchange Rate Mechanism that day. The episode damaged the credibility of the Conservative government and made the pound’s ERM policy a lasting political issue. Black Wednesday was a currency crisis rather than a conventional share-price crash, but it belongs to the broader history of market turmoil because speculative trading and official intervention drove the event.