Complex sentence: Another reason for this coinage may have been that a relatively high proportion of the Spanish and Portuguese Jews had Portugal as their immediate point of departure from the Iberian peninsula, as the decree forbidding Judaism in Portugal took place some years later than the expulsion from Spain.
Split into simpler sentences: Another reason for this coinage may have been that a relatively high proportion of the Spanish and Portuguese Jews had Portugal as their immediate point of departure from the Iberian peninsula. Portugal issued its decree forbidding Judaism in the state some years later than the expulsion from Spain.