He was a member of the dynasty known to historians as the Giselbertiners (or Giselbertini).
Lanfranc was the son of Giselbert I of Bergamo and Rotruda of Pavia.
[1] Lanfranc is first documented as a royal vassal (vassus regis) in 935.
By 945 he was entitled count (probably of Bergamo) in a diploma issued by Hugh of Italy.
Later that year Lanfranc became count palatine of Bergamo through the intervention of Berengar II of Italy.