It is suggested, without documentation or proof, that he was born in Innsbruck, by Gaetano Moroni (1861). *Dizionario di erudizione storico-ecclesiastica (in Italian). Vol. CII. Venezia: dalla Tipografia Emiliana. p. 426.
Gregorovius, p. 96, with note 1, quoting Radulphus' "Life of S. Lietbertus": Martin Bouquet (1767). Recueil des historiens des Gaules et de la France (in French and Latin). Vol. Tome onzieme (11). Paris: I.F. Delatour. p. 481. Gregorovius dates the trip in July 1056.
Louis Duchesne (1892). Le liber pontificalis (in Latin). Vol. II. Paris: E. Thorin. p. 277. The count of 13 days is approximately correct, if the beginning point is the date of Pope Victor's enthronement. The other numbers would imply his official choice by the Emperor Henry III on 31 March or 1 April 1055.