Answer:
Napoleon overthrew their monarchies in Europe.
Step-by-step explanation:
The Spanish and Portuguese colonial empires weakened due to a combination of factors, including economic, political, and social changes.
One of the main reasons was the decline in the economic power of Spain and Portugal, which could not keep up with the growing industrialization of the rest of Europe. As a result, they could not maintain their trade monopolies and were surpassed by other European powers like Britain and France.
Another factor was the increasing dissatisfaction among the colonies with the authoritarian rule of the Peninsulares (Spaniards and Portuguese born in Europe), who held all the critical positions of power and wealth. In contrast, the Creoles (Spaniards and Portuguese born in the Americas) and other non-European groups were excluded from political and economic power.
Furthermore, the Napoleonic Wars in Europe significantly impacted the colonial empires, as the French invaded Spain and Portugal, overthrowing their monarchies and disrupting their colonial systems.
All of these factors contributed to the weakening of the Spanish and Portuguese colonial empires and paved the way for the independence movements in their American colonies.