Isarn, Bishop of Grenoble

Isarn was the Bishop of Grenoble from 950 until his death in 976. During the reign of Conrad the Peaceful he was instrumental in re-asserting Christian political authority in the south of the Kingdom of Burgundy, overrun by Saracens, and in restoring the shattered Church in the region. His methods in expelling the Saracens from his diocese, were similar to those used by his successful contemporary, William the Liberator in Provence.

Isarn belonged to the family of the counts of Graisivaudan (Gravaisdun), a precursor district of the Dauphiné, whose patronage of abbeys and proprietary churches resulted in considerable control of the local church at the time. Isarn was loyal to the diocese, however, being one of the few noblemen of the region not to flee the conquest of Grenoble by the Saracens. In 965 Isarn led a counterattack against the Saracens ("Moors") and removed them from his diocese.

In 972 a raiding party of Saracens from Fraxinetum captured Mayeuil, abbot of Cluny, while he was returning from a visit to Rome. According to Archibald Lewis, "it was this action which probably at last forced action against them." Isarn began a programme of encastellation to bring the Dauphiné back under Christian control. According to later sources, the bishop had in fact begun his castle-building programme not long after 950. Between that date and 974 Isarn had many castles constructed throughout his diocese, over all of which he maintained dominatio et servitia (lordship and service). He also pursued the re-cultivation of abandoned soil and the restoration of abandoned churches and monasteries.

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