The canton of (the) Grisons, or canton of Graubünden, is the largest and easternmost canton of Switzerland. It has international borders with Italy, Austria, and Liechtenstein. Its German name, Graubünden, translates as the "Grey Leagues", referring to the canton's origin in three local alliances, the League of God's House, the Grey League, and the League of the Ten Jurisdictions. Grisons is the only officially trilingual canton and the only one where the Romansh language has official status. Swiss German, Italian, and Romansh are all native to the canton. The Romansh name of the canton, Grischun, translates literally as the "Big Grey", while La Grischa translates as "The Grey", referring to the Grey League.
Most of the lands of the canton were once part of a Roman province called Raetia, which was established in 15 BC. The current capital of Grisons, Chur, was known as Curia in Roman times. The area later was part of the lands of the diocese of Chur.
In 1367 the League of God's House (Cadi, Gottes Haus, Ca' di Dio) was founded to resist the rising power of the Bishop of Chur. This was followed by the establishment of the Grey League (Grauer Bund), sometimes called Oberbund, in 1395 in the Upper Rhine valley. The name Grey League is derived from the homespun grey clothes worn by the people and was used exclusively after 16 March 1424. The name of this league later gave its name to the canton of Grisons. A third league was established in 1436 by the people of ten bailiwicks in the former Toggenburg countship, as the dynasty of Toggenburg had become extinct. The league was called League of the Ten Jurisdictions (Zehngerichtebund).
The first step towards the canton of Grisons was when the league of the Ten Jurisdictions allied with the League of God's House in 1450. In 1471 the two leagues allied with the Grey League. In 1497 and 1498 the Leagues allied with the Old Swiss Confederacy after the Habsburgs acquired the possessions of the extinct Toggenburg dynasty in 1496, siding with the Confederacy in the Swabian War three years later. The Habsburgs were defeated at Calven Gorge and Dornach, helping the Swiss Confederation and the allied leagues of the canton of Grisons to be recognised. However the Three Leagues remained a loose association until the Bundesbrief of 23 September 1524.
The last traces of the Bishop of Chur's jurisdiction were abolished in 1526. The Musso war of 1520 drove the Three Leagues closer to the Swiss Confederacy.
The canton joined Switzerland in 1803 but issued its own coinage until the formation of the modern federal state of Switzerland in 1848 which imposed a single currency in 1850, replacing all former cantonal currencies.