Koine Greek (Greek: Ελληνιστική Κοινή[1] IPA: [kɔɪnɛ̝^], Mod.Gk. IPA: [kʲiˈni e̞liniˈkʲi], "common Greek", or ἡ κοινὴ διάλεκτος, Mod.Gk. [i kʲiˈni ðiˈale̞kto̞s], "the common dialect") is the popular form of Greek which emerged in post-Classical antiquity (c.300 BC – AD 300). Other names are Alexandrian, Hellenistic, Patristic, Common, Biblical or New Testament Greek. Original names were koine, Hellenic, Alexandrian and Macedonian (Macedonic);[2][3] all on the contrast to Attic dialect. Koine was the first common supra-regional dialect in Greece and came to serve as a lingua franca for the eastern Mediterranean and ancient Near East throughout the Roman period. It was also the original language of the New Testament of the Christian Bible and of the Septuagint (the greek translation of the Old Testament).[4] Koine is the main ancestor of modern Greek.
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The linguistic roots of the Common Greek dialect had been unclear since ancient times. During the Hellenistic age, most scholars thought of Koine as the result of the mixture of the four main Ancient Greek dialects, "ἡ ἐκ τῶν τεττάρων συνεστῶσα" (the composition of the Four). This view was supported in the early 20th century by Austrian linguist P. Kretschmer in his book "Die Entstehung der Koine" (1901), while the German scholar Wilamowitz and the French linguist Antoine Meillet, based on the intense Ionic elements of the Koine — such as σσ instead of ττ and ρσ instead of ρρ (θάλασσα — θάλαττα, ἀρσενικός — ἀρρενικός) — considered Koine to be a simplified form of Ionic.[4] The final answer which is academically accepted today was given by the Greek linguist G. N. Hatzidakis, who proved that, despite the "composition of the Four",
the "stable nucleus" of Koine Greek is Attic. In other words, Koine Greek can be regarded as Attic with the admixture of elements especially from Ionic, but also from other dialects. The degree of importance of the non-Attic linguistic elements on Koine can vary depending on the region of the Hellenistic World.[4] In that respect, the varieties of Koine spoken in the Ionian colonies of Asia Minor and Cyprus would have more intense Ionic characteristics than others.
The literary Koine of the Hellenistic age resembles Attic in such a degree that it is often mentioned as Common Attic.[4]