Complex sentence: The city is divided into two municipalities called San Ándres and San Pedro, a division which has its origin in the Toltec-Chichimeca conquest of the city in the 12th century.
Split into simpler sentences: The city is divided into two municipalities called San Ándres and San Pedro. This division originates in the Toltec-Chichimeca conquest of the city in the 12th century.