My friend Gino obtained permission to make copies from microfilm of this 12th century manuscript of 'The life of Saint Arbogast'' from the Biblioteca Apostolica Vaticana. He said "For brevity I highlighted the parts that will translate into comment. According to this document, the fact that Dagobert II may have had a son (of which, however, he is not named) was absolutely plausible. This doesn't mean that this was Sigebert IV nor that he survived his father. This is mentioned [Dagobert II] EC confirms a note of life itself in "Patrologiae Cursus Completus" tomus CXXXIV (printed in 1853) where it reads "hujus Dagobertum nominis secundum intelligere debemus".
With thanks to Gino for being able to reproduce this.
Welcome to the blog of Rhedesium
My name is Sandy Hamblett, inspired and passionate researcher of the mysteries at Rennes-les-Bains.