Koine Greek is the universal dialect of the Greek language

Greek language

Greek is an independent branch of the Indo-European family of languages. Native to the southern Balkans, it has the longest documented history of any Indo-European language, spanning 34 centuries of written records. Its writing system has been the Greek alphabet for the majority of its history;...

 spoken throughout post-Classical antiquity

Classical antiquity

Classical antiquity is a broad term for a long period of cultural history centered on the Mediterranean Sea, comprising the interlocking civilizations of ancient Greece and ancient Rome, collectively known as the Greco-Roman world...

 (c. 300 BC – AD 300), developing from the Attic dialect, with admixture of elements especially from Ionic

Ionic Greek

Ionic Greek was a subdialect of the Attic–Ionic dialect group of Ancient Greek .-History:Ionic dialect appears to have spread originally from the Greek mainland across the Aegean at the time of the Dorian invasions, around the 11th Century B.C.By the end of the Greek Dark Ages in the 5th Century...

.

Koine, the first supra-regional Greek dialect, came to serve as the lingua franca

Lingua franca

A lingua franca is a language systematically used to make communication possible between people not sharing a mother tongue, in particular when it is a third language, distinct from both mother tongues.-Characteristics:"Lingua franca" is a functionally defined term, independent of the linguistic...

of the Western world

Western world

The Western world, also known as the West and the Occident , is a term referring to the countries of Western Europe , the countries of the Americas, as well all countries of Northern and Central Europe, Australia and New Zealand...

 following the conquests of Alexander the Great. Although superseded in the West Roman Empire

Western Roman Empire

The Western Roman Empire was the western half of the Roman Empire after its division by Diocletian in 285; the other half of the Roman Empire was the Eastern Roman Empire, commonly referred to today as the Byzantine Empire....

 by Vulgar Latin

Vulgar Latin

Vulgar Latin is any of the nonstandard forms of Latin from which the Romance languages developed. Because of its nonstandard nature, it had no official orthography. All written works used Classical Latin, with very few exceptions...

, it retained its dominance in the East

Byzantine Empire

The Byzantine Empire was the Eastern Roman Empire during the periods of Late Antiquity and the Middle Ages, centred on the capital of Constantinople. Known simply as the Roman Empire or Romania to its inhabitants and neighbours, the Empire was the direct continuation of the Ancient Roman State...

, forming the basis of medieval Greek

Medieval Greek

Medieval Greek, also known as Byzantine Greek, is the stage of the Greek language between the beginning of the Middle Ages around 600 and the Ottoman conquest of the city of Constantinople in 1453. The latter date marked the end of the Middle Ages in Southeast Europe...

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