The Cataclysm was an event which ended the reign of the elven god-king and started the current era in the history of Efinia. It was a great magical disaster during which the gods returned to caring for the species of Efinia.
The God-King was an elven ruler who ascended to godhood and ruled Efinia for a 1000 years during the New Divine Era. Near the year 1000 NDE his ambition grew bigger and he wanted to seize the realm of the gods for himself. The God-King and his court mages prepared a spell which was supposed to take the king there. When a portal was opened gods entered Efinia instead andkilled the God-King.
The gods' intrusion and opening of the portal disturbed the magical energy of Efinia and resulted in natural and magical disasters happening all over the world. One of these disasters created the great lake on the continent of Efin taking many villages and cities down. It is said that the flooded settlements still hold massive treasures.
When the Cataclysm ended Efinia was devastated. Countries fell, cities and villages were in ruins and hundreds of thousands of people died. Gods returned to their realm, but this time they were assisting the sapient species in rebuilding and creating new world order.