Why did Edward III borrow money from Italian, English, and Flemish bankers?

Edward III borrowed extensively from Italian, English, and Flemish bankers primarily to finance his costly military campaigns, particularly the Hundred Years’ War against France and his earlier conflicts in Scotland.1234

The king’s need for capital was driven by the transition away from traditional feudal recruitment; his armies were increasingly formed by contract, requiring him to pay wages to soldiers and cover the significant expenses of campaigning. To secure these loans, Edward III often used wool exports, customs revenues, and future taxes as collateral.413

His reckless borrowing, particularly from prominent Italian firms like the Bardi and Peruzzi families, led to a severe financial crisis by 1339–1340, when he was estimated to owe £300,000. This debt eventually contributed to the bankruptcy of these major banking houses, as the English crown defaulted on its obligations and canceled massive debts.132