Cadi ([kɐˈdi]ⓘ), the Sursilvan for "House of God" (Casa Dei), is the historical name of Disentis Abbey and its feudal territories, later part of the Grey League.
The territories in the upper Anterior Rhine valley (Surselva) were given to Disentis Abbey, and thus removed from the direct rule of Raetia Curiensis, by Tello, Bishop of Chur (d. 765).
Sursassiala comprised the modern municipalities of Disentis/Mustér, Medel (Lucmagn) and Tujetsch (the latter containing the upper reaches of the Anterior Rhine, with no permanent settlements until the 9th century), Sutsassiala included Sumvitg, Trun and Breil/Brigels.
Until 1851, Cadi was divided into four jurisdictions (cuorts) Disentis, Tujetsch, Brigels with Medel, and Trun with Sumvitg.
The new cantonal constitution of 1851 abandoned the courts, establishing the modern municipalities, forming the Circul da Cadi (Kreis Disentis) within Vorderrhein District (1851–2000), briefly Surselva District (2001–2016), and since 2017 within Surselva Region.