Pre-Plutonian

The Pre-Plutonian Eon is the oldest (informal) eon of Espan History, and it is commonly accepted to have begun close to 5223 million (about 5.223 billion) years ago when Espa first formed formed.

The period came to a cataclysmic end when the young Espa was hit by another planet ~5.09 BYA, starting the Plutonian Eon.