Why did Napoleon’s intervention in Spain encourage self-government in Argentina?

Napoleon’s intervention in Spain, which began in 1808, served as a critical catalyst for self-government in Argentina by creating a power vacuum that challenged the legitimacy of colonial rule.123

When Napoleon imprisoned the Spanish king, Ferdinand VII, and placed his brother Joseph Bonaparte on the throne, Spain was plunged into a civil war between rival governments. This created an interregnum—a period without a recognized, lawful monarch.14

Under ancient principles of Spanish law, Argentine Creoles argued that because the king was removed, his dominions in the Americas possessed the right to govern themselves until a lawful monarch could be restored. Utilizing the cabildo—a municipal council that served as a rare forum for local political experience—prominent citizens in Buenos Aires convened an "open" town meeting. On May 25, 1810, this body established an autonomous government to administer the Viceroyalty of the Río de la Plata in the name of the exiled Ferdinand VII, effectively launching the movement toward independence.143