from The American Heritage® Dictionary of the English Language, 4th Edition
- n. A dialect of Greek that developed primarily from Attic and became the common language of the Hellenistic world, from which later stages of Greek are descended.
- n. A lingua franca.
- n. A regional dialect or language that becomes the standard language over a wider area, losing its most extreme local features.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- proper n. The "common" Greek language that developed and flourished between 300 BCE and 300 CE (the time of the Roman Empire), and from which Modern Greek descended. It was based on the Attic and Ionian dialects of Ancient Greek.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. a common language used by speakers of different languages
- n. a Greek dialect that flourished under the Roman Empire
The emergent common language, known as Koine, is the language of the New Testament and the source of Modern Greek.
Of course there are dialects that broke off and preserved Archaic characteristics even from Doric and Ionic, but we're talking about the 'Koine'.
Naturally the elders of Macedon at that time spoke Greek - the "Koine" of the Near East - in the same way as black Zimbabweans use English.
'Koine' language was only used by the Patriarchate of Constantinople which sought to suppress anything 'slavonic' in nature.
Embedded in Koine Greek, and preserved in Latin translations of the Bible, a few Hebrew terms were widely employed in Old English, such as amen and alleluia, Hebrew for “so be it” and “praise Yah,” more often rendered “verily” and “praise the Lord.”
Marcus Aurelius wrote the 12 books of the Meditations in "highly-educated" Koine Greek  as a source for his own guidance and self-improvement.
I think that the Magi – all of them – have to be Persian, because that word has extremely strong connotations (adopted from Persian by Koine and Latin), specifically the regarding the Magians, ie. the Zoroastrian priests.
I have him as a professor, and I can truly see the great knowledge for the Koine Greek he has translated.
By contrast, even the ancient near eastern speakers of low, or Koine Greek could name their reactions with far more precision.
In introducing this novelty to the congregation, I pointed out that Koine Greek was the language in which the prayer was first written down Matthew 6:9–13 and Luke 11:2–4.