A "Vita" of Fridolin (or Fridold) was written by one Balther ("Baltherus"), a monk of Säckingen, ostensibly dated to the 10th century but possibly a forgery of the mid-11th century. According to Johann Peter Kirsch, this is the earliest extant reference to the saint and he concludes that Balther relied on an earlier verbal tradition for the information recorded in his work. No earlier author mentions Fridolin; Balther's life does not provide historical or chronological context, and includes a great number miracles and visions. It has therefore mostly been dismissed as unhistorical. Most modern historians justly reject the life as unauthentic, and as having no historical foundation, while the older historians believed that it contained a germ of truth.