List of bishops of the Roman Catholic Diocese of Sion :
 
Late Antiquity 
Bishops of Agaunum (Octodurum)   
From
 
To
 
Bishop
 
Notes
  
fl. 380s
 
 
Theodore 
 
  
fl. 440
 
 
Salvius/Silvius
 
  
fl. 490
 
 
Prothais
 
  
 
516(?)
 
Theodore II (?)
 
  
517
 
 
Constantinus
 
  
549
 
 
Rufus
 
  
565
 
 
Agricola
 
  
Early Middle Ages 
From
 
To
 
Bishop
 
Notes
  
585
 
 
Heliodorus
 
  
613
 
614
 
Leudemond
 
  
647
 
653
 
Prothais
 
  
673
 
690
 
Saint Aimé 
 
  
762
 
765
 
Willicar
 
  
786/8
 
796/8
 
Altheus
 
  
fl. 805
 
 
Theodore III (?)
 
According to 12th-century legend, secular power was granted to the bishops of Sion by Charlemagne 
  
fl. 824
 
 
Adalongus
 
  
825
 
857
 
Heyminus
 
  
877
 
899/900
 
Waltherius
 
  
932
 
 
Asmundus
 
  
fl. 940
 
 
Manfredus (?)
 
  
983
 
984/5
 
Amizo
 
  
Prince-bishops of Sion 
 
Middle Ages 
From
 
To
 
Bishop
 
Notes
  
993/4
 
1018/20
 
Hugues
 
First prince-bishop, granted secular power by Rudolph III of Burgundy  in c. 999
  
1034
 
1053/4
 
Aymon of Savoy
 
Succeeded his  brother Buchardus as Abbot of St Maurice in 1049 or 1050
  
1054
 
1087-1090
 
Ermenfroi
 
  
fl. 1092
 
 
Gausbertus
 
  
1107
 
1116
 
Vilencus
 
  
1135
 
1138
 
Boson
 
  
1138
 
1150
 
Saint Guérin 
 
  
1150
 
1162(?)
 
Louis
 
  
1162
 
1168 (?)
 
Amédée of La Tour
 
  
1176
 
1177
 
Guillaume of Blonay
 
  
1179
 
1181 or 1184
 
Conon
 
  
1184(?)
 
1196
 
Guillaume of Candie
 
  
1196
 
1203
 
Nantelme of Écublens
 
  
1203
 
1205
 
Guillaume of Saillon
 
  
1206
 
1237
 
Landry of Mont
 
  
1237
 
1243
 
Boson II of Granges
 
  
1243
 
1271
 
Henri of Rarogne 
 
  
1271
 
1273
 
Rodolphe of Valpelline
 
  
1273
 
1287
 
Pierre of Oron
 
  
February 1287
 
15 December 1289
 
 
vacant 
 
1289
 
1308
 
Boniface of Challant
 
  
1308
 
1323
 
Aymon of Châtillon
 
  
1323
 
1338
 
Aymon of La Tour
 
  
1338
 
1342
 
Philippe of Chamberlhac
 
  
1342
 
1375
 
Guichard Tavelli
 
Murdered by defenestration
  
1375
 
1386
 
Édouard of Savoy
 
  
Western Schism 
loyal to Avignon   
From
 
To
 
Bishop
 
Notes
  
1386
 
1386
 
Guillaume of La Baume-Saint-Amourb
 
  
1387
 
1387
 
Robert Chambrier
 
  
1388
 
1392
 
Humbert de Billens
 
  
1398
 
1404
 
Aymon Séchala
 
  
1404
 
1417
 
Jacques (Antoine?) de Challant
 
  
loyal to Rome  
From
 
To
 
Bishop
 
Notes
  
1387
 
1388
 
Gerardus (Girard Tavel?)
 
  
1392
 
1393
 
Henri de Blanchis
 
  
1394
 
1402
 
Guillaume IV ("the Good") of Rarogne 
 
  
1402
 
1418
 
Guillaume V of Rarogne 
 
see Raron affair 
  
Renaissance to early modern 
Coat of arms of Hildebrand of Riedmatten	(1594).  The prince-bishops used their family coats of arms;  the Riedmatten  coat of arms was in use for much of the early modern period (1529–1545, 1565–1613, 1640–1701) and is  presented as coat of arms of the bishopric in e.g. Siebmacher (1605) .  
From
 
To
 
Bishop
 
Notes
  
1418
 
1437
 
André dei Benzi of Gualdo
 
Archbishop of Kolocza (in Hungary); administrator from 1418, bishop from 1431. Valais witch trials .
  
1437
 
1451
 
Guillaume VI of Rarogne 
 
  
1451
 
1457
 
Henri Asperlin
 
  
1457
 
1482
 
Walter Supersaxo 
 
Burgundian War 
 
1482
 
1496
 
Jost of Silenen  (d. 1498)
 
Member of Lucerne nobility (uncle of Kaspar von Silenen ) and diplomat for the Swiss Confederacy, bishop of Grenoble  1477–1467, Jost ruled as a "Renaissance prince" but after failed campaigns against Milan was forced to abdicate and went into exile in Lyon, retaining only the title of titular bishop  of Hierapolis .
  
1496
 
1499
 
Nicolas Schiner
 
  
1499
 
1522
 
Mathieu Schiner 
 
Cardinal; nephew of Nicolas Schiner
  
1522
 
1528
 
Philippe am Hengart (not recognised by the Pope) 
Philippe de Platea (not recognised locally)
 
  
1529
 
1545
 
Adrien I of Riedmatten
 
Valais becomes an eternal associate of the Old Swiss Confederacy  in 1529.
  
1548
 
1565
 
Jean Jordan
 
  
1565
 
1604
 
Hildebrand I of Riedmatten
 
Banned protestantism  in 1604[ 1]  
  
1604
 
1613
 
Adrien II of Riedmatten
 
  
1613
 
1638
 
Hildebrand II Jost
 
In 1628, the Valais becomes a republic, but remains under the nominal rule of the prince-bishops.
  
1638
 
1640
 
Barthélemy Supersaxo 
 
  
1640
 
1646
 
Adrien III of Riedmatten
 
  
1646
 
1672
 
Adrien IV of Riedmatten
 
  
1672
 
1701
 
Adrien V of Riedmatten
 
  
1701
 
1734
 
François-Joseph Supersaxo 
 
  
1734
 
1752
 
Jean-Joseph-Arnold Blatter
 
  
1752
 
1760
 
Jean-Hildebrand Roten
 
  
1760
 
1780
 
François-Joseph-Frédéric Ambuel
 
  
1780
 
1790
 
François-Melchior-Joseph Zen-Ruffinen
 
  
1790
 
1807
 
Joseph Anton Blatter 
 
Last prince-bishop, loss of secular power with the French invasion  of 1798.
  
Modern history 
Modern coat of arms  
From
 
To
 
Bishop
 
Notes
  
1807
 
1817
 
Joseph-François-Xavier de Preux
 
  
1817
 
1829
 
Auguste-Sulpice Zen-Ruffinen
 
  
1830
 
1843
 
Maurice-Fabien Roten
 
  
1843
 
1875
 
Pierre-Joseph de Preux
 
  
1875
 
1901
 
Adrien VI Jardinier
 
  
1901
 
11 July 1918
 
Jules-Maurice Abbet
 
Born 11 September 1845
  
1919
 
19 March 1952
 
Victor Bieler
 
Born 16 March 1881
  
1952
 
1975
 
François-Nestor Adam
 
Born 7 February 1903; died 8 February 1990
  
1975
 
1995
 
Henri Schwery 
 
Born 14 June 1932
  
1995
 
2014
 
Norbert Brunner 
 
Born 21 June 1942
  
2014
 
 
Jean-Marie Lovey
 
Born 2 August 1950
  
References