As lord of Chios, Martino and Benedetto fought with distinction against the Turkish pirates, who made their appearance in the Aegean in the early years of the 14th century. In 1304, the capture of Ephesus by the emirate of Menteshe had sparked the Genoese occupation of Chios, and raids against the Aegean islands intensified over the next years. The Emirate of Aydin soon emerged as the chief Turkish maritime emirate, especially under the leadership of Umur Bey, while the Zaccaria, along with the Knights Hospitaller of Rhodes, became the two main Latin antagonists of the Turkish pirates. The Zaccaria are reported to have maintained a thousand infantry, a hundred horsemen and a couple of galleys on constant alert. In 1317, they lost the citadel of Smyrna on the Anatolian coast to the Aydinids, but continued to hold on to the lower city until 1329, when Umur Bey captured it. In 1319, however, Martino Zaccaria participated with seven ships in a Hospitaller fleet that scored a crushing victory over an Aydinid fleet from Ephesus. By the end of his rule on Chios, Martino is said to have taken captive or slain more than 10,000 Turks, and received an annual tribute in order not to attack them. His constant efforts against the Turkish pirates earned him great praise by contemporary Latin writers, who wrote that if not for his vigilance, "neither man, nor woman, nor dog, nor cat, nor any live animal could have remained in any of the neighbouring islands". Martino also intervened to stop the slave trade carried out by the Genoese of Alexandria, for which he was praised by Pope John XXII. In exchange, the Pope granted him the right to export mastic to Egypt—an exemption to the papal ban on trade with the Mamluks of Egypt—and proposed that the Zaccaria be given command of the Latin fleets in the Aegean.
