Geological / environmental event
A particularly dry year hit the Sagely Grounds, and consequently Asceroth. The Kingdom held on, taking great assistance from Nobolia.
A drought a few years after the Kingdom of Asceroth's founding caused an island-wide famine, Asceroth struggled but it was able to hang on with help from Nobolia.
The Raxarians on the island did not fare so well though, and more were lost to the unstoppable scourge of time.