The dissertation focuses on the political economy of the Portuguese and Spanish empires during the Age of Revolutions, tracing the rise of Rio de Janeiro and Havana as global cities. It examines the political economy of the emergence of two global ports in the LusoHispanic Atlantic and appraises institutional dynamics instead of merely exploring the nature of institutions. This work contributes to the field of global history by offering an Atlantic history in global perspective. It proposes a Hemispherical Atlantic and simultaneously discloses its connections with the Indian Ocean. As a substitute of a local/global dichotomy, the dissertation resorts to the use of three different dimensions (markets, institutions and agents), which do not necessarily follow a path from global to local. The first part analyses the cities’ integration into imperial and global markets as well as their participation into much larger global commodity chains. It considers not only markets’ trends but also the emergence of translocal markets. The financing of Slave trade in the South Atlantic and flour trades in the North Atlantic are thoroughly researched. The second section emphasises on institutions and their impact on agent’s behaviour. It mainly refers to formal institutions as well as their dynamics. It fundamentally focuses on institutions governing exchange: customs houses, taxes and corporations, and carefully integrates emulation in the design, creation and evolution of formal institutions. Finally, the third section explores networks, agency relations and privateorder institutions. Besides trust and reputation, merchants’ status was crucial in the configuration and evolution of networks. Credit, multidirectional capital flows, and the consignment system are studied through the meticulous examination of merchants businesses in Africa, New England and the Peninsula, offering new insights on Asian textiles in the Caribbean markets and the slave traffic in Brazil. This thesis investigates the complexities of governance that took place in the Iberian empires, and revises images of absolutist power, centralization or negotiation. It argues that the empire’s organization was highly hierarchical (which differs from centralization) and claims that such a rigid hierarchical organization prevented to some extend institutional change and innovation. In so doing, it underlines the need for an intermediate approach between “black legend” absolutist versions and revisionist “pink histories” of the Iberian empires.