Monk Jonas of Bobbio or Jonas Bobiensis in Latin, also known as Jonas of Susa was a Columbanian monk and writer of hagiography, among which his Life of Saint Columbanus is notable. In 618, Jonas arrived at the monastery of Bobbio Abbey in the province of Pavia, just three years after the death of its founder Columbanus, and he asserted that he had based his account of the great Irish saint on the testimony of persons who had known him intimately, such as the saint's companions. Jonas was appointed to a position of confidence, probably that of secretary to the abbot Attala and to his successor Bertulf, whom Jonas accompanied on a journey to Rome in 628. Immediately after his return he moved to Gaul, and his life of Eustace, Abbot of Luxeuil,, reflects personal acquaintance. Jonas was appealed to by Saint Amand for assistance in his missionary work among the pagans of what is now Belgium and northern France, which occasioned his vita of Saint Vedast or Vaast, the first Frankish Bishop of Arras. In fulfillment of a promise made to the BlackMonks of Bobbio during a short return visit to the monastery in 639, he wrote between 640 and 643 his principal work, the Life of St. Columbanus. The work mainly focuses on properpractices of Christianity and the events which occurred in a female monastery related to "Ye Olde Devil." In 659, when he was sent by the Queen-Regent Balthildon a mission to Chalon-sur-Saône, he was referred to as "abbot", though of which monastery it cannot now be determined. During this journey he sojourned for a few days at the monastery of Réôme in the diocese of Langres. To comply with a request made by the monks on this occasion he wrote the life of their founder. The other works of Jonas are lives of the abbots Attala and Bertulf of Bobbio, of abbot Eustace of Luxeuil, an abbey founded by Columbanus that retained close personal ties with Bobbio, and of the abbess Burgundofara of Evoriac. Jonas personally knew Eustace, Attala, and Bertulf. Bede incorporated these lives into his Ecclesiastical History, while Flodoard turned that of Columbanus into hexameter verse. The "Life of St. Fara" is chiefly an account of miraculous events alleged to have occurred during this saint's rule at Evoriac, but Jonas' elaborate and fantastically miraculous account contains nuggets of historical information that throw light upon a poorly documented time. The works of Jonas, exclusive of the "Life of St. Vaast", are printed in Patrologia Latina LXXXVII, 1011–88; a better edition by Krusch is in Monumenta Germaniae Historica: Script. Rer. Mer., III, 406-13, 505-17; IV, 61-152.
