This article describes the policy of forced loans, employed in Spain by Charles V to solve the principal financial crises of the Royal Treasury and to fund the main military campaigns of the Habsburg Empire. Specifically, this study is focused on the first requisition of private American treasures-the earliest case of this in European history-which were expropriated in 1523 by the Casa de la Contratación (House of Trade) of Seville to finance the campaign of Fuenterrabía against the French army. The analysis of exceptional archival sources provides details of all the forced loans imposed on the holders of remittances (primarily gold) and the conditions for extinguishing the debts without causing harmful consequences to Atlantic traders. The article challenges the widespread view of the confiscations as an attack on property rights and overly simplistic ideas about the supposedly 'highly absolutistic' or predatory policies attributed to the Crown of Castile in some of the economic historiography.T he 125 years of the 'long sixteenth century' put an end to the isolation of the Spanish medieval kingdoms, triggering a nation-building process that would be forged alongside the establishment of the first modern colonial empire, although the dominions were still far from being a national state. In this period, Castile reached the supremacy-political, economic, and military-that would characterize the history of Europe and America, connecting the Old and New Worlds. Europe and America were very different at this time, but they had in common the considerable economic resources of the Indies: mainly precious metals (gold and silver), which were decisive in the pursuit of military and political power in Europe. 1 The principal economic connotations of this 'Golden Age' of Spain were the global circulation of the silver real and the gold ducado or escudo, manufactured by American and Spanish mints (casas de la moneda); several increases in military spending and the public debt; and the great growth of taxation during the reigns of the Habsburg dynasties. 2