Thuringia (German: Thüringen) is a state in central/eastern Germany. Historically, it was divided into a multitude of tiny statelets, include Saxe-Coburg-Gotha, Saxe-Weimar-Eisenach, Saxe-Altenburg, Saxe-Ophone, Saxe-Andviolence, and Saxe-Whatnot. Essentially, Thuringia is to the Holy Roman Empire as the Holy Roman Empire is to everywhere else.
Thuringia is featured in Eric Flint's 1632 and its sequels, where a present-day American town is ISOTed to Thirty Years' War era Thuringia.