The Promulgation of the Constitution of Cádiz was a constitutional response to the collapse of Spanish authority under French invasion, but its promise of popular sovereignty and legal equality also sharpened conflict in Spain’s American colonies. In Mexico, the prospect that the constitution would limit elite privileges helped turn a Spanish constitutional crisis into a decision for independence.

Invasion and Constitutional Crisis

In February 1808, French armies invaded Spain; by May they had taken Madrid, and by September King Ferdinand VII had been captured and abdicated. The Junta Central assumed the struggle against the French, moving from Aranjuez toward Cádiz as the invading forces advanced. Although besieged, the port held out, and the Junta established a parliament there, the Cortes. In 1812, the Cortes produced a constitution proposing a constitutional monarchy founded on popular sovereignty.

Principles and Colonial Resistance

The constitution also called for ending special privileges and establishing equality before the law. Those principles directly threatened the colonial order in which South American elites exercised authority through institutions shaped by the encomienda, forced labor, and extensive power vested in elites and the colonial state. The constitutional project therefore did not present itself to those elites as a neutral reform: it challenged the privileges on which their authority rested.

The Spanish state’s collapse created a wider crisis over who had the right to rule in the colonies. Disputes about whether to recognize the Junta Central prompted many Latin Americans to form their own juntas, making separation from Spain increasingly conceivable. In Mexico, elite attitudes were also shaped by the 1810 Hidalgo Revolt. After Father Miguel Hidalgo’s army sacked Guanajuato on September 23, it killed the senior colonial official and then killed white residents indiscriminately. The episode appeared more like class or ethnic conflict than a movement capable of reassuring the elite, and it united elites against the possibility of popular political participation. They consequently viewed the Cádiz Constitution with extreme skepticism and refused to recognize its legitimacy.

Restoration and Renewed Imposition

In 1815, after Napoleon’s European empire collapsed, Ferdinand VII returned to power and the constitution was abrogated. The Spanish Crown then sought to recover its American colonies, but loyalist Mexico did not initially pose a problem. The situation changed in 1820, when an army assembled in Cádiz to sail to the Americas mutinied against Ferdinand. Army units elsewhere in Spain joined the revolt, compelling the king to restore the constitution and recall the Cortes.

The recalled Cortes was more radical than the body that had written the 1812 constitution. It proposed abolishing all forms of labor coercion and attacked special privileges, including the military’s right to try its members in separate courts. Once this constitutional program faced imposition in Mexico, local elites chose separation rather than accept changes they considered threatening to their position. The constitution thus became a catalyst for independence not simply because it proposed popular sovereignty, but because its renewed enforcement brought its challenges to elite privilege into immediate focus.

Legacy and Institutional Contrast

The Mexican response illustrates the book’s broader distinction between formal constitutional principles and the interests and constraints that determine whether they are accepted. In this account, the Cádiz Constitution’s commitments to participation and equality could not overcome the opposition of elites whose power depended on the colonial order. Their rejection helped direct independence toward a settlement that would preserve elite status rather than open politics broadly.

The episode also contrasts with the longer constitutional process in the United States, which the book traces from the formation of the Virginia General Assembly in Jamestown in 1619 to the drafting of the U.S. Constitution in Philadelphia in 1787. The comparison treats political institutions, rather than constitutional language alone, as decisive: a constitution’s effect depends on who can shape and enforce it, and on whether those holding power are constrained by it. In Mexico, the Cádiz Constitution’s return exposed the limits of constitutional reform when its principles threatened entrenched interests and helped precipitate independence on terms designed to protect them.