[1] The conquests of Alexander the Great, and the ensuing Hellenistic period, had caused Greek to spread to peoples throughout Anatolia and the Eastern Mediterranean, altering the spoken language's pronunciation and structure.

Nonetheless, the imperial court resided there and the city was the political centre of the eastern parts of the Roman Empire where Greek was the dominant language.

Despite the absence of reliable demographic figures, it has been estimated that less than one third of the inhabitants of the Eastern Roman Empire, around eight million people, were native speakers of Greek.

The invasion of the Slavs into the Balkan Peninsula reduced the area where Greek and Latin was spoken (roughly north of a line from Montenegro to Varna on the Black Sea in Bulgaria).

In the Byzantine era, written Greek manifested itself in a whole spectrum of divergent registers, all of which were consciously archaic in comparison with the contemporary spoken vernacular, but in different degrees.

These are influenced by the vernacular language of their time in choice of words and idiom, but largely follow the models of written Koine in their morphology and syntax.

In fifteen-syllable blank verse (versus politicus), the Digenes Akritas deals with both ancient and medieval heroic sagas, but also with stories of animals and plants.

Cypriot Greek was already in a literary form in the late Middle Ages, being used in the Assizes of Cyprus and the chronicles of Leontios Makhairas and Georgios Boustronios.

Up to this point, transliterations into Georgian continue using a different letter for υ/οι than for ι/ει/η,[11] and in the year 1030, Michael the Grammarian could still make fun of the bishop of Philomelion for confusing ι for υ.

[12] In the 10th century, Georgian transliterations begin using the letter representing /u/ (უ) for υ/οι, in line with the alternative development in certain dialects like Tsakonian, Megaran and South Italian Greek where /y/ reverted to /u/.

[13] In the original closing diphthongs αυ, ευ and ηυ, the offglide [u] had developed into a consonantal [v] or [f] early on (possibly through an intermediate stage of [β] and [ɸ]).

[16] In many cases, the vowel o disappeared in the endings -ιον [-ion] and -ιος [-ios] (σακκίον [sa'cion] → σακκίν [sa'cin], χαρτίον [xar'tion] → χαρτίν [xar'tin], κύριος ['cyrios] → κύρις ['cyris]).

The velar sounds /k, x, ɣ, ŋk, ŋɡ/ (κ, χ, γ, γκ, γγ) were realised as palatal allophones ([c, ç, ʝ, ɲc, ɲɟ]) before front vowels.

The fricative /h/, which had been present in Classical Greek, had been lost early on, although it continued to be reflected in spelling through the rough breathing, a diacritic mark added to vowels.

On the other hand, some scholars contend that post-nasal voicing of voiceless plosives began already in the Koine, as interchanges with β, δ, and γ in this position are found in the papyri.

[23] The prenasalized voiced spirants μβ, νδ and γγ were still plosives by this time, causing a merger between μβ/μπ, νδ/ντ and γγ/γκ, which would remain except within educated varieties, where spelling pronunciations did make for segments such as [ɱv, n̪ð, ŋɣ][24] Many decisive changes between Ancient and Modern Greek were completed by c. 1100 AD.

There is a striking reduction of inflectional categories inherited from Indo-European, especially in the verbal system, and a complementary tendency of developing new analytical formations and periphrastic constructions.

Feminine nouns ending in -ις [-is] and -ας [-as] formed the nominative according to the accusative -ιδα [-iða] -αδα [-aða], as in ἐλπίς [elpís] → ἐλπίδα [elˈpiða] ('hope'), πατρίς [patrís] → πατρίδα [paˈtriða] ('homeland'), and in Ἑλλάς [hellás] → Ἑλλάδα [eˈlaða] ('Greece').

Thus, in Ancient Greek the stem of the verb λαμβάνειν [lambáneːn] ('to take') appears in the variants λαμβ- [lamb-], λαβ- [lab-], ληψ- [lɛːps-], ληφ- [lɛːpʰ-] and λημ- [lɛːm-].

[citation needed] Byzantine research played an important role in the Greek State, which was refounded in 1832, as the young nation tried to restore its cultural identity through antique and orthodox-medieval traditions.

The following texts clearly illustrate the case of diglossia in Byzantine Greek, as they date from roughly the same time but show marked differences in terms of grammar and lexicon, and likely in phonology as well.

As seen in the phonetic transcription, although most major sound changes resulting in the Modern Greek system (including the merger of υ/οι /y/ with /i/) are assumed complete by this period, learned speech likely resisted the loss of final ν, aphaeresis and synizesis.

ἀνύστακτος γὰρ ὤν ὁ δοὺξ Δυρραχίου, μὴ διδοὺς τὸ παράπαν ὕπνον τοῖς ὀφθαλμοῖς, ὁπηνίκα διέγνω διαπλωσάμενον τὸν Βαϊμούντον παρὰ τὴν τοῦ Ἰλλυρικοῦ πεδιάδα καὶ τῆς νηὸς ἀποβεβηκότα καὶ αὐτόθι που πηξάμενον χάρακα, Σκύθην μεταπεψάμενος ὑπόπτερον δή, τὸ τοῦ λόγου, πρὸς τὸν αὐτοκράτορα τὴν τούτου διαπεραίωσιν ἐδήλου.o ðe vasiˈlefs, ˈeti is tim vasiˈlevusan enðjaˈtrivon, memaθiˈkos ðja ɣraˈfon tu ðuˈkos ðiraˈçiu tin du vaiˈmundu ðjapeˈreosin epeˈtaçine tin eˈkselefsin.

aˈnistaktos ɣar on o ðuks ðiraˈçiu, mi ðiˈðus to paˈrapan ˈipnon tis ofθalˈmis, opiˈnika ˈðjeɣno ðjaploˈsamenon tom vaiˈmundon para tin du iliriˈku peˈðjaða ce tiz niˈos apoveviˈkota ce afˈtoθi pu piˈksamenon ˈxaraka, ˈsciθin metapemˈpsamenos iˈpopteron ði, to tu ˈloɣu, pros ton aftoˈkratora tin ˈdutu ðjapeˈreosin eˈðilu.

For the duke had been vigilant, having altogether denied sleep to his eyes, and at the moment when he learned that Bohemond had sailed over beside the plain of Illyricum, disembarked, and set up camp thereabouts, he sent for a Scythian with "wings", as the saying goes, and informed the emperor of the man's crossing.

[26] Καὶcὡςosεἴδασινˈiðasinτὰtἀδέλφιαaˈðelfjaτηςtisτὴνtiŋκόρηνˈɡorinμαραμένην,maraˈmeni(n)Καὶ ὡς εἴδασιν τὰ ἀδέλφια της τὴν κόρην μαραμένην,c os ˈiðasin t aˈðelfja tis tiŋ ˈɡorin maraˈmeni(n)ἀντάμαanˈdamaοἱiπέντεˈpendeἐστέναξαν,ˈstenaksan,τοιοῦτονtiˈuto(n)λόγονˈloɣonεἶπαν:ˈipa(n):ἀντάμα οἱ πέντε ἐστέναξαν, τοιοῦτον λόγον εἶπαν:anˈdama i ˈpende ˈstenaksan, tiˈuto(n) ˈloɣon ˈipa(n):'Ἐγείρου,eˈjiru,ἠiβεργόλικος,verˈɣolikos,γλυκύνɣliˈci(m)μαςmasτὸtoἀδέλφιν˙aˈðelfi(n);'Ἐγείρου, ἠ βεργόλικος, γλυκύν μας τὸ ἀδέλφιν˙eˈjiru, i verˈɣolikos, ɣliˈci(m) mas to aˈðelfi(n);ἐμεῖςeˈmisγὰρɣarἐκρατοῦμανekraˈtumanσεseὡςosγιὰjaἀποθαμένηνapoθaˈmeni(n)ἐμεῖς γὰρ ἐκρατοῦμαν σε ὡς γιὰ ἀποθαμένηνeˈmis ɣar ekraˈtuman se os ja apoθaˈmeni(n)καὶcἐσὲνeˈsenὁoΘεὸςˈθjosἐφύλαξενeˈfilakse(n)διὰ(ð)jaτὰtὡραῖαoˈreaσουsuκάλλη.ˈkali.καὶ ἐσὲν ὁ Θεὸς ἐφύλαξεν διὰ τὰ ὡραῖα σου κάλλη.c eˈsen o ˈθjos eˈfilakse(n) (ð)ja t oˈrea su ˈkali.Πολέμουςpoˈlemusοὐuφοβούμεθαfoˈvumeθaδιὰðiˈaτὴνtiσὴνˈsinἀγάπην.

'poˈlemus u foˈvumeθa ðiˈa ti ˈsin aˈɣapi(n)'And when her brothers saw the girl withered, the five groaned together, and spoke as follows: "Arise, lissom one, our sweet sister; we had you for dead, but you were protected by God for your beautiful looks.

As there had already been extensive exchange with Italian academics since the 14th century, many scholars and a large number of manuscripts found their way to Italy during the decline of the Eastern Roman Empire.

The Bavarian scholar Karl Krumbacher (1856–1909) carried out research in the newly founded state of Greece, and is considered the founder of Medieval and Modern Greek Philology.

[citation needed] Byzantinology also plays a large role in the other countries on the Balkan Peninsula, as Byzantine sources are often very important for the history of each individual people.