Aragon was a kingdom on the Iberian Peninsula whose union with Castile in 1492 formed the dynastic foundation of Spain. Its political institutions, especially the limited reach of its Cortes, helped shape the monarchy’s growing absolutism and the extractive economic order that the book contrasts with England’s more pluralistic trajectory.

Union and the Spanish Monarchy

The crowns of Aragon and Castile were joined through the marriage of Queen Isabella and King Ferdinand. The book presents this 1492 union as the beginning of a larger consolidation: dynastic marriages and inheritances subsequently extended the monarchy’s reach beyond the peninsula. By 1516, Charles, the son of Joanna and Philip of the House of Habsburg, had been crowned Charles I of Castile and Aragon. He later inherited the Netherlands and Franche-Comté, and, after the death of Maximilian I in 1519, the Habsburg territories in Germany; as Emperor Charles V, he ruled a far-flung empire.

The growth of this monarchy was supported by wealth from the Americas. The Spanish Crown received a share of conquest and mining revenues, including silver from Potosí, while its political authority strengthened. Aragon’s union with Castile thus belongs to a sequence in which dynastic consolidation and overseas wealth helped build a powerful state; the book emphasizes, however, that state power and broad-based prosperity did not necessarily grow together.

The Cortes and Royal Authority

Aragon had a Cortes, an assembly representing groups of the kingdom, as did Castile. Like the English Parliament, the Cortes was associated with assent to new taxes. But the Aragonese and Castilian assemblies primarily represented major cities, rather than encompassing urban and rural interests as the English Parliament did. By the fifteenth century, the Cortes represented only eighteen cities, each sending two deputies. It did not legislate, and its authority over taxation was limited.

That restricted representation mattered politically. The Cortes did not become a strong forum in which diverse interests could coordinate and constrain royal power. Its limited reach made it easier for the Spanish monarchy to sideline the assembly as it consolidated absolutism. The comparison with England is not simply one between a kingdom with an assembly and one without: it turns on how broadly institutions represented social groups and how effectively they could limit the Crown.

Institutional Divergence and Its Consequences

The book uses the contrasting paths of England and Spain to show how small institutional differences could become consequential at moments of disruption. Atlantic trade opened substantial opportunities, but in Spain the monarchy organized colonial trade through a merchant guild in Seville, concentrating control and helping ensure that wealth flowed to the Crown. The narrow, regulated system limited the emergence of a broad class of merchants with independent interests. The weaker representative institutions of Castile and Aragon formed part of the political setting in which this extractive arrangement could take hold.

The argument is not that Aragon’s institutional arrangements mechanically determined every later outcome. Rather, inherited differences shaped how societies responded to critical junctures. The book describes institutional development as contingent: small distinctions could accumulate or recede, then matter greatly when new economic or political circumstances disrupted the existing balance. Aragon’s Cortes is therefore significant less as an isolated institution than as part of the contrast between Spain’s increasingly centralized monarchy and England’s eventual expansion of parliamentary authority.