The information from this article is from the fan game King's Quest II: Romancing the Stones or fan fiction and is therefore not canon.

Eusperia is a kingdom near Daventry. The realm of Eusperia was once multitude of fueding regions, and became a united kingdom. It was once unable to defend itself, but now as a whole, it is able to defend itself with a large standing army. They had become a strong nation and was seeking an alliance with Daventry. Gervain felt it prudent that Daventry show its support lest the kingdom thought Daventry was hindrence more than help. The present lord of the realm is said to be king, generous, and wise. The King has no daughters that have come of age.

The port of Eusperia has markets where they sell slaves. Pirates who sell between Llewdor and Eusperia sometimes sell slaves at those markets.