There are six dioceses in Switzerland (Basel, Lausanne-Geneva-Fribourg, Sion, Lugano, Chur, St. Gallen) and two territorial abbeys (St. Maurice, Einsiedeln). As opposed to many other countries, Swiss dioceses are not incorporated into an ecclesiastical province but are directly controlled by the Holy See. Cooperation between the dioceses takes place on a national level in the Episcopal Conference of Switzerland (SBK). The SBK was founded in 1863 and was the world’s first conference of a country’s bishops. The large Swiss dioceses are divided into regions and organised in deaneries or vicariates, each comprising a number of neighbouring parishes.
A particular feature of the Roman Catholic Church in Switzerland is the dual system which exists in large parts of the country. Its bodies are divided into two areas, each with different functions. Alongside the bodies of ecclesiastical law (dioceses, parishes), which primarily take care of church management, pastoral matters, proclamation and sacraments, there are also bodies of state law (parishes and cantonal church bodies), which are above all concerned with administrative affairs, finance, properties and real estate.

The Diocese of Basel
The first seat of the Bishop of Basel was Augusta Raurica (Kaiseraugst). It was in this town that one of the earliest Christian communities formed on the territory of modern-day Switzerland during the first half of the 4th century. The bishop’s seat was relocated to Basel during the Carolingian period. In the Middle Ages, Basel developed into the intellectual and spiritual centre of Northern Alsace. Basel had particular ecclesiastical significance at the end of the Middle Ages with the Council of Basel (1431-1449) and it is thanks to the Council of Basel that the city’s university was founded. With the start of the Reformation, the bishop moved his residence from Basel to the prince-bishop castle in Porrentruy in 1527, although the cathedral chapter remained in Basel. Two years later, the canons and chaplains who had not been converted by the Reformation settled in the Catholic Freiburg im Breisgau. With this move, Basel ceased to be the seat of the bishop and the cathedral chapter for ever more. In 1679, the bishop and the chapter decided to establish a new residence in Arlesheim. With the outbreak of the French Revolution in 1789, they had to leave Arlesheim and go into exile. Due to a concordat between Basel, Lucerne, Solothurn and Zug and the Pope, the Diocese of Basel, with the bishop’s seat in Solothurn, was newly established in 1828.

The Diocese of Lausanne, Geneva and Fribourg
The territories of the late antiquity Dioceses of Lausanne and Geneva, which had become Swiss, were combined into the bishop’s seat in Fribourg. The former Diocese of Lausanne has its origins in the Roman city of Aventicum. Towards the end of the 5th century, the bishop moved his seat to Lausanne. The territory of the diocese, which stretched from Nyon to Solothurn, was initially under the overall control of the Bishops of Lyon and later the Bishops of Besançon. The origins of the former Diocese of Geneva go back to the 4th century. The Diocese of Geneva was initially under the control of the Archdiocese of Vienna. During the Reformation, the Bishops of Geneva and Lausanne had to flee to Savoy. In 1613, the Bishop of Lausanne settled in Fribourg. Following Geneva’s admission to the Swiss Confederation in 1815, the now Swiss territories of the former Diocese of Geneva were allocated to the Diocese of Lausanne.

The Diocese of Sion
The Diocese of Sion has its origins in the ancient Diocese of Octodurus, which also included parts of the later Diocese of Lausanne. The bishop’s seat was initially in Martigny, but it was moved to Sion in the 6th century.

The Diocese of Lugano
Ecclesiastically, Ticino belonged to the Dioceses of Como and Milan until 1888. Ticino, as apostolic administrator, initially remained under the control of the Diocese of Basel, as the Swiss Federal Constitution prohibited the founding of new dioceses. It was only in 1971 that the Apostolic Administration was officially separated from the Diocese of Basel and the new status of the diocese was sealed.

The Diocese of Chur
The Diocese of Chur probably developed in the 4th century on the territory of Raetia Curiensis. Ecclesiastically, the Diocese of Chur first belonged to the Archdiocese of Milan. After the division of the Frankish Empire in 843 to 1803, it was under the control of the Archdiocese of Mainz and since then, has been under the direct control of the Pope. During the Middle Ages, the Bishop of Chur controlled large parts of the present-day Grisons, Chiavenna, Bormio and Vinschgau in his capacity as secular leader and Prince-Bishop of the Holy Roman Empire. He was constantly feuding with his officials on the one hand, and the rival landowners on the other hand. In the 14th century, the earldoms of Chiavenna and Bormio were lost to Milan, as were Vinschgau and parts of Vorarlberg later on. In 1819, the Diocese of Chur gained Ob- and Nidwalden and parts of Uri, Schwyz, Glarus and Zurich from the dissolved Diocese of Constance for provisional administration. In 1823, the Papal Bull founded the newly formed Diocese of Chur-St. Gallen, from which the Diocese of St. Gallen split in 1847.

The Diocese of St. Gallen
Ecclesiastically, North-East and South-West Switzerland belonged to the Diocese of Constance until it was split from Constance in 1814. After the division, the Diocese of Chur-St. Gallen was founded in 1823; St. Gallen did not agree with this, however. To end the long-running dispute, an Apostolic Vicariate for St. Gallen was founded, from which the Diocese of St. Gallen was created in 1847.

The Archdiocese of Vaduz
The Archdiocese of Vaduz was founded in 1997. Prior to that, the area, as the Deanery of Liechtenstein, was part of the Diocese of Chur.

The Abbey of St. Maurice
The Abbey of St. Maurice was founded in 515 on the tomb of Saint Maurice. It is the oldest monastery in the western world which has existed without interruption. The Abbey has the status of territorial abbey with the parishes of St. Maurice, Vernayaz, Salvan and Finahaut.

The Abbey of Einsiedeln
The abbey was founded in 934 and originally belonged to the Diocese of Constance. Following the dissolution of the Diocese of Constance, the abbey joined the Diocese of Chur, provisionally in 1819 and definitively in 1824. The abbey has had territorial abbey status since 1907 and does not belong to any diocese.

The Parish of Saint-Gingolgph VS is the only Swiss community to belong to a foreign diocese (the Diocese of Annecy).