Complex sentence: As the Spaniards worked towards consolidating the rule of New Spain over the indigenous peoples during the sixteenth and seventeenth centuries, the Chichimecan nations resisted fiercely, although a number of native groups of the region allied with the Spanish.
Split into simpler sentences: As the Spaniards worked towards consolidating the rule of New Spain over the indigenous peoples during the sixteenth and seventeenth centuries, the Chichimecan nations resisted fiercely. A number of native groups of the region allied with the Spanish.