On the morning of July 27, 1956, mere hours after Egyptian President Gamal Abdel Nasser had announced from a stage in Alexandria that he was nationalizing the Suez Canal, the Bank of England, in coordination with the British Treasury, froze the Egyptian government’s sterling accounts and barred the residents of Egypt from transacting in British pounds anywhere in the world. A barrage of telegrams went out to central banks across the globe announcing the terms of this monetary blockade. The speed with which Britain was able to coordinate this punitive monetary blockade might at first seem surprising, but this was no improvised measure. For well over two years before the stunning events of July 1956, amidst growing alarm at the perceived threat that Nasser posed to imperial interests within and beyond the Middle East, officials the Bank and the Treasury had worked carefully to devise a set of exchange restrictions “of the utmost severity” that would be “ready to impose at 24 hours’ notice or less should the situation in Egypt appear to warrant it.” This monetary weapon that British officials devised offers a starting point from which to reconsider the political economy of decolonization in Egypt and the place of the Suez Crisis in that longer process. Most accounts this period read Nasser’s decision to nationalize the waterway as a grab for capital to fund the Aswan High Dam. Drawing on a vast corpus of central bank records, this paper argues instead that the dramatic events of 1956 are better understood as the culmination of a decade-long struggle to delink the Egyptian pound from sterling and establish a viable national currency with which Egypt would be free to conduct the global transactions necessary for the country’s new development projects.