Unterwalden (Latinized as Sylvania, later also Subsylvania as opposed to Supersylvania) is the old name of a forest-canton of the Old Swiss Confederacy in central Switzerland, south of Lake Lucerne, consisting of two valleys or Talschaften, now organized as two half-cantons, an upper part, Obwalden, and a lower part, Nidwalden.Unterwalden is one of the three participants in the foundation of the Old Swiss Confederacy, named in the Pact of Brunnen of 1315 with Uri and Schwyz.The division of Unterwalden into two separate territories, Obwalden and Nidwalden in the early period is less than clear.
Unterwalden figures as communitas hominum Intramontanorum Vallis Inferioris "community of the men between the mountains of the Lower Valley" in the Federal Charter of 1291; this is usually rendered as "the community of the Lower Valley of Unterwalden" in modern translations, and interpreted as Nidwalden or "Unterwalden proper".
While Nidwalden and Obwalden may or may not have existed as independent sub-entities of Unterwalden during 1291-1315, there is an internal division between Obwalden and Nidwalden at least from 1350.
