What are the major historical periods of the Greek language?

The history of the Greek language is generally categorized into several major developmental periods:

• Mycenaean Greek: The most ancient form of Greek, dating to the 2nd millennium BCE. It was a chancellery language used for administrative records, written in the Linear B syllabic script.12
• Ancient Greek: Spanning roughly the 8th to the 4th century BCE, this period was characterized by a variety of mutually intelligible dialects, such as the Ionic-Attic, Aeolic, and Doric groups. During this time, literature flourished in various dialectal forms.3
• Koine Greek: Emerging in the Hellenistic period (4th century BCE), this "common" language was based primarily on the Attic dialect. It became a uniform lingua franca across the Mediterranean and Middle East, serving as the language of the New Testament and the Septuagint.43
• Byzantine Greek: Spoken and written during the Byzantine Empire until 1453. While the written language often followed an archaizing, "Atticist" style, the spoken language underwent significant phonological and grammatical changes that moved it closer to modern forms.5
• Modern Greek: Developing after the medieval period, this stage is defined by the convergence of the vernacular Demotic and the formal, archaizing Katharevusa. Since 1976, Demotic has been the official language of Greece.67