Complex sentence: Migration of Moroccans to The Netherlands is a part of Moroccan migration to Western Europe which dates back to the beginning of the 1960's when the economic and social situation in Morocco was highly complicated.
Split into simpler sentences: Migration of Moroccans to the Netherlands is a part of a general pattern of Moroccan migration to Western Europe. This migration dates back to the beginning of the 1960's when the economic and social situation in Morocco was highly complicated.