Jonas (d. p.659), monk and biographer of Columbanus (qv), Atalanus, and later abbots of Bobbio, was born at Susa, Piedmont in northern Italy. He entered Bobbio c.617/18 and remained there till c.640, serving under Abbots Atalanus and Bertulf. He also spent some time at the monasteries of Luxeuil and Faremoutiers. It is possible that in 638 he supported the mission of Bishop Amandus to Scarpe, Schelde, and Elnon. He may at one time have been abbot of Marchiennes, one of Amandus's foundations; he was also possibly abbot of the community of St Amand for a period.
Having entered Bobbio within a few years of Columbanus's death (615), Jonas was acquainted with many people who had known the saint. His ‘Life of Columbanus and his disciples’ was commissioned by Abbot Bertulf and the Bobbio community and was written between 639 and 642. The work presented Columbanus as a staunch defender of orthodoxy against Arianism. Being mainly intended for monks and nuns, however, it concentrated on Columbanus's lifestyle and the way of life of his disciples after his death. Despite its ornate and florid style, it is one of the finest hagiographical works composed in Merovingian Gaul, the prologue being an especially fine composition. It draws on a wide range of patristic and hagiographical sources, and is replete with biblical allusions. Jonas also composed other hagiographies, authorship of the ‘Vita Vedastis episcopi Atrebatensis’ and the ‘Vita Iohannis abbatis Reomaensis’ being attributed to him by Krusch.