Hesse /ˈhɛs/ or Hessia (German: Hessen [ˈhɛsn̩], Hessian dialect: Hesse [ˈhɛzə]) is a federal state (Land) of the Federal Republic of Germany, with just over six million inhabitants. The state capital is Wiesbaden; the largest city is Frankfurt am Main. Until the formation of the German Reich in 1871, Hesse was an independent country ruled by a Grand Duke (Grand Duchy of Hesse). Due to divisions after World War II, the modern federal state does not cover the entire cultural region of Hesse which includes both the State of Hesse and the area known as Rhenish Hesse (Rheinhessen) in the neighbouring state of Rhineland-Palatinate.
The English name "Hesse" originates in the Hessian dialects. The variant "Hessia" comes from the medieval Latin Hassia. The German term Hessen is used by the European Commission because their policy is to leave regional names untranslated (paragraphs 1.31 & 1.35). The term "Hesse" ultimately derives from a Germanic tribe called the Chatti, who settled in the region in the first century B.C. An inhabitant of Hesse is called a Hessian (German: Hesse (masculine) or Hessin (feminine)). The synthetic element hassium, number 108 on the periodic table, is named after the state of Hesse.