The ancestors of the Laz people are cited by many classical authors from Scylax to Procopius and Agathias, but the Laz (Greek: Λαζοί) themselves are cited by Pliny around the 2nd century BC, The ethnonym "Laz" is unhesitatingly linked to a Svan toponym La-zan (i.e. La = territorial prefix + Zan).
By the 6th century, the Colchians of Pontus were known as the Tzanni (Ancient Greek: Τζάννοι), at the same time when the Caucasian state of Lazica (or Egrisi in Georgian sources) existed on the Phasis valley basin. According to Procopius, the Byzantine emperor Justinian I subdued Tzanni in the 520s and converted them to Christianity. When the ancient metropolis, Phasis, was lost by the Byzantine Empire, Trebizond became the Metropolitan bishop of Lazica, since then the name Lazi appears the general Greek name for the southern Colchian tribes (Greek: Τζανοί, translit. Tzanoi) lying outside of the direct control of the Lazic Kingdom.
The Pontic Lazi, which were incorporated within the Byzantine Empire, and differed from the Caucasian Lazi, or Megrelians, have retained the old name "Lazi" till today.