He was the second son of Sergius II[2] and Maria, sister of Pandulf IV of Capua.
In 1029, John, but not Sergius, returned and reasserted his authority, deposing Manso and Maria.
In April or May 1034, John was forced to flee Amalfi again for Naples and Manso and Maria retook the throne with the support of Pandulf.
In 1038, the Holy Roman Emperor Conrad II deposed Pandulf and John was able to return to Amalfi.
He blinded Manso and exiled him to the island of Sirenuse, with the support of Maria, whom he allowed to co-reign.