Résumé : In order to finance the Italian war, Henry II ‘financial advisers have made in 1555 an enormous financial operation in LYON – then the French financial capital: a huge debt consolidation plus a cash issue. This issue was outstandingly “modern” by at least three aspects. 1. The subscription was reserved to the institutional investors --- the merchant-bankers. 2. For the first time, the amortization took the form of a 41-quarterly –constant-annuities system. 3. Because of a huge demand, an incredible system of “assimilation” of new loans has been organized. The end of this loan is as stupendous as its technics: less than two years later, the Royal government defaulted and only 9% of the total issue has been repaid according to schedule.