Asia Minor... area inhabited in early period of existence of the Empire by the Greeks, the Izaurians, the Celts, the Armenians, the Arabs, the Jews, the Persians and other, more or less numerous peoples. During the 7th century into that melting pot of ethnic groups penetrated also Slavs, some of whom migrated to that region of their own free will, while others were resettled there [by Byzantine rulers] with use of force.
[such resettlements of Slavs from the Balkans - both prisoners of war from independent tribes and subjects from conquered tribes - into Asia Minor were organized by Byzantine Emperors in years: 656 AD, as well as ca. 690 AD, ca. 710 AD - after victory over Bulgars in the battle of Salonica - and later by Emperor Constantine V (741-775) and by Empress regnant Irene of Athens (after 780)]
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Some Slavic tribes migrated to Asia Minor - with permission from Byzantine Emperors - of their own free will:
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According to account by Nikephoros I after internal struggles for power between Bulgarian clans in the 760s and the takeover of power by Khan Telec, who supported hostile policies towards the Byzantine Empire and Slavic tribes, over 200,000 Slavs asked the Emperor for asylum. The Emperor granted them asylum and entire mass of people settled in Bithynia along the Artanas River and in the region of Sinope. Other, perhaps not that numerous, Slavic communities were settled by Byzantine authorities as military settlers (to defend the borders) near the Byzantine-Arab border, and later, near the borders with Turkish states.
From among Slavic settlers and prisoners of war arised some of well-known Byzantine historical figures. Some of them left good impression of themselves, some other caused chaos and left bloody stains in chronicles. For example in 779 died the Patriarch of Constantinople, Nicetas, who was of Slavic descent. 44 years later died famous Thomas, known as the Slav. This Thomas in 820 gained support from the Arabs and from European provinces of the Empire, and declared himself the new Emperor. He fought bloody and fierce combats against his counter-candidates to the throne. During the rebellion of Thomas, his antagonist - Michael II - was concerned that Peloponnesian Slavic tribes would support Thomas, but the rebellion probably had more of a political and economic than "national" or ethnic background.
Slavic communities living in Asia Minor were getting assimilated relatively slowly. In 949 Byzantine units preparing to recapture Crete from Muslim hands consisted mostly of Slavs recruited from Slavic communities living in the region of Opsikon. What is interesting, those units were also led by Slavic commanders. Even after dozens of years, there were still Slavic-speaking communities in Bithynia. One of them was called Sagoudaos. John II Comnenus (1118 - 1143) contributed to the strengthening of Slavic ethnos in that region, colonizing some areas near Nicomedia with captured Serbian prisoners. Information about Serbian settlements in that region continue to appear even during the 13th century.
In 663 AD a group of 5,000 Slavs supported the Arab invasion under certain Abderachman, son of Chaledos. After the invasion they returned with his army to Arab lands and settled in Syria in the region of Apamea, in and near the town of Seleukobolos. Several dozen years later another group of Slavic traitors (traitors to the Byzantines, not to themselves) - 20,000 under the leadership of certain Nebulos - supported the Arabs. In reward for their support, Arab Caliph granted them land to settle in northern Syria, near Antioch.
In 737 Muslim army (numbering according to sources even 100,000 men), under command of certain Marwan (future Caliph) attacked Slavic-inhabited lands of the Khazar realm. When returning back to his land, Marwan took with him 20,000 Slavic families (!) and settled them in his land.
In the 9th century in Muslim lands there were large Slavic-speaking communities for example near al-Chusus (near the Arab-Byzantine border), in Hisn Salman (near Aleppo), near Hisn Zijad (at the upper Euphrates). According to one Muslim writer in the 9th century there were also enclaves of independent, self-governing Slavic communities in southern Armenia - and they were still Pagan (!).
Some Slavs achieved high-ranking status in the Arab world. During the reign of Marwan ibn Muhammad (744-750), his chamberlain was a liberated slave, and he was ethnically Slavic (according to Al-Baladuri). Two individuals of Slavic descent (but converted to Islam) - Salman and Zijad - were commanders of Muslim armies fighting in Armenia and Asia Minor in the mid-8th century. Slavs were especially favoured by Fatimid rules. Certain Muzaffat, Slavic by descent, was in 952 - 975 the governor of the eastern part of the Caliphate. And Slavic general of Fatimid armies - Dzauha - conquered Egypt for this dynasty, and founded the city of Cairo.
Slavs also lived in cities and villages of Arabic Mesopotamia - usually they were slaves, and according to one of Muslim early 9th century poets, their number was so great that the streets of Baghdad looked like fields infested by locust (he could easily distinguish Slavs from locals, because Slavs had fair skin and most of them had fair hair).
Muslim "ethnographer" - Al-Gahiz - wrote some opinions about ethnic Slavs living in what is today Iraq, both free people (settlers) and slaves. For example, he wrote:
"Slavs are more avaricious than the Byzantines."
Another of his opinions was:
"When among two Slavic brothers, coming from the same mother and the same father, even if they are twins, you castrate one (and not the other one), then this castrate will become better in working, smarter, more clever and more suitable to various kinds of services and manual labour. You will also find him to be more intelligent in discussion."
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And one more of his (Al-Gahiz's) opinions:
"Among Slavs, abominable and ugly are their smoothness of hair [as opposed to curly hair] and delicateness, as well as blonde or ruddy colour of their hair and of their beards, as well as whiteness [bright blonde colour] of their eyelashes."
And one more philosophical consideration by Al-Gahiz (who was apparently "brown"):
"Tell me friend, after how many generations a Zang became black, and a Slav became white?"
