Koiné (from κοινή, "common") Greek was the form of post-classical Greek spoken and written in Hellenistic and Roman antiquity. It is the language of the Septuagint (LXX), Christian New Testament, and most early Christian theological writings.

Koiné (from κοινή, "common") Greek was the form of post-classical Greek spoken and written in Hellenistic and Roman antiquity. It is the language of the Septuagint (abbreviated as "LXX" - the pre-Christian Greek translation of the Hebrew scriptures), Christian New Testament, and most early Christian theological writings.

The language developed under the spread of Hellenic culture by Alexander the Great during the 4th century BCE and became the lingua franca of the Roman Empire and surrounding regions, continuing on into the Byzantine Empire until approximately 600 CE.

Further information on texts, grammar, and historical development can be found in a Q&A on Meta.Hermeneutics.SE.