Jonatus of Marchiennes

Saint Jonatus of Marchiennes was a disciple of Saint Amandus and abbot of Marchiennes in French Flanders, and then of Elnone. He reposed on 1 August, around 690 or 695.

He was a monk at Elnone under Abbot Amandus. According to the Annals of Marchiennes he was the first abbot of Marchiennes from 641 (the calendars say 643 to 652). The monastery had been founded as a male community by Amandus, but Jonatus introduced nuns not long after he became abbot; the first nun was Rictrude. Around 652 he became the third abbot of Elnone; according to one twelfth-⁠century source, he governed Elnone on two separate occasions, first before becoming abbot of Marchiennes and then holding both abbeys simultaneously while Amandus was on his third pilgrimage to Rome. He spent his later years at Marchiennes.

The earliest source for his life is the work of Hucbald; in the twelfth century Galbert of Marchiennes wrote an account of his posthumous miracles, the Miracula Ionati. All these sources were written after the Viking raids of the late ninth century had resulted in the loss of Marchiennes's original documents. He is listed on 1 August in the 2004 Roman Martyrology; the translation of his relics was celebrated around Marchiennes into modern times on 8 April. The Orthodox calendar commemorates him on 1 August as a saint of the undivided Church, by the New Calendar.