Complex sentence: The family came originally from Westphalia and they came later to the Netherlands into the cities The Hague, Wassenaar, Leiden and belonged also to the political elite and the upper class of these cities.
Split into simpler sentences: The family came originally from Westphalia and they came later to the Netherlands into the cities The Hague, Wassenaar, Leiden. It belonged to the political elite and the upper class of these cities.