The Hittite Empire eventually collapsed following invasion from the west by the Achaeans, the Phrygians, and a mysterious force known only as the  Sea People.  
The enemy forces that invaded the Hittite had a thirst for money and slaves.
mnli hypothesis: The enemy forces that invaded the Hittite had a thirst for money and slaves. premise: The Hittite Empire eventually collapsed following invasion from the west by the Achaeans, the Phrygians, and a mysterious force known only as the  Sea People.  