 The parents of Niccolò and his brother Francesco I Gattilusio are not known, although based on the heraldic evidence of their inscriptions, Anthony Luttrell argues that their mother was a member of the Doria family.He accompanied his brother in his adventures.As the former was rewarded by the Byzantine emperor John V Palaiologos with the island of Lesbos, so Niccolò received the coastal city of Ainos, which he took title to at some point between 1376 and 1379.