Acquitaine: The Realm of the Summer King

From publisher blurb: Acquitaine describes the kingdom of the same name. It’s part of the Tuala Morn setting (which is described in the book of the same name from Hero Games), but can be used by itself or as part of another world. It covers the history, society, lands, and nobles of the “Summer Kingdom.” It also includes a magic system (with several new spells) and six new monsters.