According to the account of Isidore of Seville (Iberian Peninsula) in De viris illustribus 44, John was a Goth from Lusitania, he studied in Constantinople. He went back to Spain during the reign of Leovigild, and was said to be persecuted for his Catholic faith. Later he founded the monastery in Biclar, and eventually he was ordained as bishop of Gerona (Iberian Peninsula). He wrote a chronicle as a continuation of the work of Eusebius, Jerome, Victor of Tunnuna and Prosper of Aquitaine. His point of departure was AD 567, and he reached the year AD 592 (Wolf 2011: 1-9).