Complex sentence: This reflected an historical division of Holland along the IJ into a Southern Quarter ("Zuiderkwartier ") and a Northern Quarter ("Noorderkwartier"), but the actual division is different from the old division.
Split into simpler sentences: This reflected an historical division of Holland along the IJ into a Southern Quarter ("Zuiderkwartier ") and a Northern Quarter ("Noorderkwartier"). But the actual division is different from the old division.