Britain’s departure from the exchange rate mechanism of the European Monetary System on September 16 1992 — a day that came to be known as “Black Wednesday” — had important consequences. One might see this as the beginning of the UK’s slow separation from the EU that culminated in the Brexit vote last year.

Many countries in the Exchange Rate Mechanism system of fixed exchange rates with relatively narrow bands underestimated its weaknesses, particularly its vulnerability to speculative attacks. A speculator acting on the expectation of a member country devaluing could expect high profits, but practically no risk if devaluation did not arise.

During her visit to Germany shortly after Black Wednesday, Queen Elizabeth asked me: “Is the speculation really so strong?” My modest answer, was: “In this system, the possibilities of profit are very high and the risks are negligible.”