The term "Eidgenossenschaft" refers to the political history of which country?

“Eidgenossenschaft” is a German word specific to the political history of Switzerland. It means ""oath commonwealth"" or ""oath alliance"", in reference to the ""eternal pacts"" formed between the Eight Cantons of the Old Swiss Confederacy in the late mediaeval period (from 1353 to 1481). In Swiss history, this relates most notably to the oath binding the three founding cantons Uri, Schwyz and Unterwalden, and dates to 1307. The word is documented from as early as 1315 in the Pact of Brunnen, referring to these cantons.

In a historical context, “Eidgenossenschaft” refers to the medieval Swiss Confederacy, which grew from the 13th to the 16th century, persisted until 1798 and then evolved into a federal state in the 19th century. When used in this sense, the eternal nature of the pact is necessary—the members of the Thirteen Cantons (from 1513 to 1798), frequently made time-limited alliances sworn by oath with other partners, but such pacts were not considered an “Eidgenossenschaft”.

In modern usage, “Eidgenossenschaft” is the German term used as an equivalent to "Confederation" in the official name of Switzerland, “Schweizerische Eidgenossenschaft” and refers to all 26 cantons. The term “Eidgenosse” (literally: “comrade by oath”) refers to individual members of the “Eidgenossenschaft”. Nowadays “Eidgenosse” is sometimes used in archaic or ironic usage for "Swiss citizen", especially for those who are citizens of purely Swiss origin and not by immigration.