Bishop Asinio of Chur was first mentioned in 451 with the diocese probably being founded in the 4th or 5th century.
 The first church on the site was built in the 5th century.
 In 1921 an excavation discovered a small apse from this first church below the current building.
 The second church was probably built by Bishop Tello before his death in 773.
 The 1921 excavation discovered a larger apse from this church.
 Additionally, some of the marble carvings in the choir are from this second church.

The current Romanesque church was begun under Bishop Adalgott (1151-60).
 The choir was consecrated in 1178, followed by the main altar in 1208.
 The church was completed and consecrated to the Assumption of the Blessed Virgin Mary in 1272 under Bishop Henry of Montfort.
 In 1462 the Chapel of S. Lawrence was added to the cathedral, followed by a sacrament house in 1484.
 A new high altar was built in 1492 by Jacob Russ.
 The St. Luzius Chapel and a prayer house for the bishop were built in 1517.
 The entire church was renovated in 1652.
 During the renovation, the upper sacristy was added.

Beginning in the 11th century, the Bishops of Chur began taking sides in secular conflicts as their worldly power grew.
 In 1079/80, during the Investiture Controversy the emperor's candidate Norbert became bishop over the pope's candidate Ulrich II of Tarasp.
 He held the office until 1087, when he was replaced by Ulrich II.
 During the conflicts between Frederick Barbarossa and Pope Alexander III following the 1159 papal election, Bishop Egino of Chur sided with the emperor and was rewarded with the dignity of Prince of the Empire (1170).
 In 1514 Emperor Maximilian I separated the land surrounding the cathedral from the town of Chur and granted it as an imperial estate to the Bishops.
 In 1524 the Protestant Reformation was accepted in Chur and the two Catholic churches of St. Martin and St. Regula were given over to the Protestants.
The bishop fled, and his administrator, Abbot Theodore Schlegel, was publicly beheaded (1 January 1529).
Bishop Thomas Planta, tried without success, to suppress Protestantism.
He died, probably poisoned, 5 May 1565.
 The Ilanz Articles of 1524 restricted the secular power of the bishop to his imperial estate, including the cathedral.
 During the Bündner Wirren, the cathedral remained a center of Catholic power in the region.
 The 1803 Act of Mediation ended the secular power of the bishop.

In 1811 a fire destroyed the towers and roof of the cathedral.
 In 1828-29 the roof was replaced and the towers were rebuilt from the ground up.
 The marble floor in the choir was added in 1852.
 In 1884-86 the west window was reglazed and a new organ was built by F. Goll of Lucerne.
 Between 1921 and 1926 the entire church was completely renovated.
 The interior was completely cleaned, some of the plaster was removed from the walls, the altars were restored and the crypt floor was excavated.
 About a decade later, in 1937-38, another organ was added by Franz Gattringer of Horn in the Canton of Thurgau.
 For the rest of the 20th century a museum was added in the crypt and additional repairs, cleaning and renovations continued.
 For about six years, beginning in 2001, the cathedral was completely renovated and new organs replaced the Goll and Gattringer organs.
 The cathedral was re-consecrated on 7 October 2007.
Bishop Asinio of Chur was first mentioned in 451 with the diocese probably being founded in the 4th or 5th century.  The first church on the site was built in the 5th century.  In 1921 an excavation discovered a small apse from this first church below the current building.  The second church was probably built by Bishop Tello before his death in 773.  The 1921 excavation discovered a larger apse from this church.  Additionally, some of the marble carvings in the choir are from this second church.
The current Romanesque church was begun under Bishop Adalgott (1151-60).  The choir was consecrated in 1178, followed by the main altar in 1208.  The church was completed and consecrated to the Assumption of the Blessed Virgin Mary in 1272 under Bishop Henry of Montfort.  In 1462 the Chapel of S. Lawrence was added to the cathedral, followed by a sacrament house in 1484.  A new high altar was built in 1492 by Jacob Russ.  The St. Luzius Chapel and a prayer house for the bishop were built in 1517.  The entire church was renovated in 1652.  During the renovation, the upper sacristy was added.
Beginning in the 11th century, the Bishops of Chur began taking sides in secular conflicts as their worldly power grew.  In 1079/80, during the Investiture Controversy the emperor's candidate Norbert became bishop over the pope's candidate Ulrich II of Tarasp.  He held the office until 1087, when he was replaced by Ulrich II.  During the conflicts between Frederick Barbarossa and Pope Alexander III following the 1159 papal election, Bishop Egino of Chur sided with the emperor and was rewarded with the dignity of Prince of the Empire (1170).  In 1514 Emperor Maximilian I separated the land surrounding the cathedral from the town of Chur and granted it as an imperial estate to the Bishops.  In 1524 the Protestant Reformation was accepted in Chur and the two Catholic churches of St. Martin and St. Regula were given over to the Protestants. The bishop fled, and his administrator, Abbot Theodore Schlegel, was publicly beheaded (1 January 1529). Bishop Thomas Planta, tried without success, to suppress Protestantism. He died, probably poisoned, 5 May 1565.  The Ilanz Articles of 1524 restricted the secular power of the bishop to his imperial estate, including the cathedral.  During the Bündner Wirren, the cathedral remained a center of Catholic power in the region.  The 1803 Act of Mediation ended the secular power of the bishop.
In 1811 a fire destroyed the towers and roof of the cathedral.  In 1828-29 the roof was replaced and the towers were rebuilt from the ground up.  The marble floor in the choir was added in 1852.  In 1884-86 the west window was reglazed and a new organ was built by F. Goll of Lucerne.  Between 1921 and 1926 the entire church was completely renovated.  The interior was completely cleaned, some of the plaster was removed from the walls, the altars were restored and the crypt floor was excavated.  About a decade later, in 1937-38, another organ was added by Franz Gattringer of Horn in the Canton of Thurgau.  For the rest of the 20th century a museum was added in the crypt and additional repairs, cleaning and renovations continued.  For about six years, beginning in 2001, the cathedral was completely renovated and new organs replaced the Goll and Gattringer organs.  The cathedral was re-consecrated on 7 October 2007.
Chur Cathedral