On 16 September 1992, a day that became known as Black Wednesday, the British pound came under intense selling pressure and effectively crashed against other major currencies after the United Kingdom withdrew from the European Exchange Rate Mechanism (ERM). The immediate cause was sustained speculative pressure on sterling: investors doubted the government’s ability to maintain the pound within the ERM’s permitted exchange-rate band while interest rates and domestic economic conditions diverged from those of Germany and other ERM partners. In the months preceding Black Wednesday, Britain had joined the ERM in October 1990 with the aim of stabilising inflation and signals of convergence with European monetary policy. By 1992, the UK economy was in recession, unemployment was rising, and inflationary and fiscal dynamics differed markedly from those in Germany following reunification. Sterling came under renewed pressure in the summer of 1992 amid widening current-account concerns, capital outflows and growing speculative positions against the pound. On 16 September, sterling opened sharply lower. The British government and the Bank of England intervened in the foreign-exchange markets and raised official interest rates—temporarily twice in the space of hours—to defend the currency. Those measures failed to stem the selling. Faced with mounting losses from intervention and an untenable position trying to keep sterling within the ERM band, the government abandoned that commitment and allowed the pound to float freely. The immediate financial consequence was a large depreciation of sterling against the Deutsche Mark and other currencies. The Bank of England’s attempt to defend the pound involved large-scale foreign-exchange operations and a brief spike in UK interest rates, but market forces overwhelmed those interventions. Many investors who had bet on a fall in sterling profited, while the government incurred substantial intervention losses. Political fallout was rapid and severe. The Conservative government, led by Prime Minister John Major, suffered a loss of credibility on economic management. Black Wednesday is widely seen as a pivotal event that damaged the Conservatives’ reputation for financial competence and contributed to their heavy defeat at the 1997 general election. Within economic policy circles, the episode intensified debate over fixed exchange-rate mechanisms versus monetary policy autonomy. In the longer term, the pound’s exit from the ERM and subsequent depreciation helped restore competitiveness to parts of the UK economy and is credited by some economists with aiding the recovery that followed. The episode also strengthened arguments for an independent domestic monetary-policy framework; in 1997 the incoming Labour government granted operational independence to the Bank of England to set interest rates, a decision often linked in historical accounts to lessons drawn from Black Wednesday. Scholars and market participants continue to analyse Black Wednesday for lessons about exchange-rate pegs, speculative attacks, and policy credibility. While the event is frequently portrayed as a dramatic crash, assessments vary: some emphasise the immediate market losses and political damage, while others underline the subsequent economic adjustments and policy changes that followed. Sources for this account include contemporaneous news reporting, later academic and economic analyses of the ERM crisis, and official financial records documenting the Bank of England’s interventions. This summary avoids technical minutiae of trading positions and proprietary data; those seeking detailed transactional records or contemporaneous internal government minutes should consult archived official papers and specialist economic histories.