Why was Cortes defeating the Aztecs so important?

Cortes' defeat of the Aztecs in 1521 was significant as it marked the beginning of Spanish colonization in the Americas, leading to profound cultural, political, and economic changes. The conquest resulted in the fall of one of the most powerful indigenous empires, paving the way for European dominance in the region. It also initiated a brutal era of exploitation and the spread of Christianity, reshaping indigenous societies and their histories. Ultimately, this event set the stage for the establishment of New Spain and the broader European colonial enterprise in the Americas.