Prince Philip, Duke of Anjou to the throne of Spain as Philip V. Under the 1715 Treaty of Utrecht, the French and the Spanish Bourbons could not unite, with Philip renouncing any rights to the French throne. The political restriction did not impede strong French influence of the Age of Enlightenment on Spain, the Spanish monarchs, the Spanish Empire. Philip came into effective power in 1715 and began implementing administrative reforms to try to stop the decline of the Spanish Empire. Under Charles III, the crown began to implement serious structural changes, generally known as the Bourbon Reforms. The crown curtailed the power of the Catholic Church and the clergy, established a standing military in Spanish America, established new viceroyalties and reorganized administrative districts into intendants. Freer trade was promoted under comercio libre in which regions could trade with companies sailing from any other Spanish port, rather than the restrictive mercantile system. The crown sent out scientific expeditions to assert Spanish sovereignty over territories it claimed but did not control, but also importantly to discover the economic potential of its far-flung empire. Botanical expeditions sought plants that could be of use to the empire. One of the best acts by Charles IV, a monarch not notable for his good judgment, was to give Prussian scientist Alexander von Humboldt free rein to travel and gather information about the Spanish Empire during his five-year, self-funded expedition. Crown officials were to aid Humboldt in any way they could, so that he was able to get access to expert information. Given that Spain's empire was closed to foreigners, Humboldt's unfettered access is quite remarkable. His observations of New Spain, published as the Political Essay on the Kingdom of New Spain remains an important scientific and historical text. When Napoleon invaded Spain in 1808, Ferdinand VII abdicated and Napoleon placed his brother Joseph Bonaparte on the throne. To add legitimacy to this move, the Bayonne Constitution was promulgated, which included representation from Spain's overseas components, but most Spaniards rejected the whole Napoleonic project. A war of national resistance erupted. The Cortes de Cádiz (parliament) was convened to rule Spain in the absence of the legitimate monarch, Ferdinand. It created a new governing document, the Constitution of 1812, which laid out three branches of government: executive, legislative, and judicial; put limits on the king by creating a constitutional monarchy; defined citizens as those in the Spanish