Who Ruled Mexico for the Spanish until 1540.?

Hernán Cortés ruled Mexico for the Spanish until 1540 after leading the expedition that resulted in the fall of the Aztec Empire. He was appointed the governor of New Spain and played a crucial role in establishing Spanish colonial rule in the region. Cortés implemented various policies to consolidate Spanish control, but his governance was marked by conflicts with indigenous populations and rival Spanish factions. His authority effectively ended when he was replaced by a more formal colonial administration.