Born around 1240 from a noble family from Genoa, he probably lived long in the East and became a prominent figure of the Byzantine Empire, thus being enfeoffed the town of Focea. It was a very prosperous fief due to the production of alum, used in leather and fabric, so sought after by traders and pirates. Zaccaria, with his fleet led by the major vessel Divitia, traded at large the precious mineral from the Black Sea, where he owned various stores, as far as Spain, monopolizing the market for several years.
When hostilities broke out between Aragon and Anjou, the latter aiming at the conquest of the Eastern Empire to assert its hegemony in the Mediterranean, Zaccaria was sent to the Spanish King Peter of Aragon by the Republic of Genoa, in support of the Aragonese, but the outbreak of the Sicilian Vespers in 1282 diverted Charles of Anjou from his military projects.
Two years after Zaccaria fought again on the seas to counter the ambitions of Pisa over Sardinia and Corsica, key outposts for the Genoese trade with North Africa: his fleet, applying the innovative practice of naval blockade, was fundamental in the dismantling of Porto Pisano. He was later involved in the battles in the Latin Kingdom of the East, but lost the favour of the Republic, and entered the service of Castile with his ships to recapture the regions in Arab hands. In exchange for his services he was enfeoffed Porto Santa Maria, near Cadiz; because of his overwhelming victory over the Moroccan fleet he obtained the title of "Admiral of the Sea.
His reputation as a strategist and leader was by then widespread in Europe, and Philip IV of France wanted him in his service, to develop and carry out an attack plan against England. After 1300 Zaccaria left France and returned to the East to defend his fiefdoms, threatened by pirates of different nationalities, and once again his intervention was requested - on this occasion by the emperor Andronicus - which granted him the fief of Chios as strategic base against piracy. But the island was also the only center of rubber production in the Mediterranean, and Zaccaria could further develop his commercial activities.
After reaching the peak of fame and fortune, the great Admiral was reconciled with his hometown, where he returned in 1308, to come to his death soon afterwards.