His cousin Bernabo succeeded him. Before that, he had been a canon at Genoa Cathedral (1302). A short time later, he confirmed Castruccio Castracani in his possessions in exchange of the sharing of the benefits from the tolls and the bishopric output, agreement which lasted until the condottiere's death in 1328. That same year, taking advantage of the weakening of Lucca county, the diocese powerful neighbours tried to retrieve a portion of the territory. Bernabo joined this new war, beside his cousin Spinetta Il Grande, the Della Scalas from Verona, the Viscontis and the Florentines. He defeated the Pisans, who left Massa and Avenza, and he entered Sarzana in 1335. He took possession of Massa the following year.

Bernabo died on August 5th, 1338 and he was buried in San Francesco church at Sarzana. An epitaph, still visible on the gravestone inside the church reads:  Sobrius et lenis, castus , misurator egenis ; Compatiens mestis et moribus aptus honestis. 

In 1351, another member of the Malaspina family was appointed bishop of Luni by Clement IV: Gabriele, son of Azzolino II, marquess of Fosdinovo, brother of Spinetta Il Grande and Bernabo, the archbishop of Pisa. Four years later, the emperor Charles IV confirmed him as bishop-count of Luni and also appointed him prince of the Holy Roman Empire.

In 1353, guelphs and ghibellines called on him to prepare the peace between the two parties, a task doomed to failure due to too strong a disagreement between the two factions.  He eventually devoted himself to his holy mission. He gave up any political, material or territorial vindication and dedicated himself to the management of the bishopric from Sarzana. Thanks to his great honesty, his uncle Spinetta Il Grande appointed him as his executor.