By the fifth century the last of the Indo-European native languages of Anatolia ceased to be spoken, replaced by Koine Greek.
At the same time the Greek communities of central Anatolia were becoming actively involved in affairs of the Byzantine Empire and some Greek Cappadocians such as Maurice Tiberius (r. 582–602) and Heraclius would even serve as Emperors.

The region became a key Byzantine military district after the advent of Islam and the subsequent Muslim conquest of Syria led to the establishment of a militarized frontier zone (cf kleisoura and thughur) on the border of Cappadocia.
This lasted from the mid-7th to the 10th century during the Arab–Byzantine wars, immortalized in Digenis Akritas, the Medieval Greek heroic epic set in this frontier region.
During this period Cappadocia became crucial to the empire and produced numerous Byzantine generals, notably the Phokas clan, warlords (see Karbeas of Tephrike), and intrigue, most importantly the Paulician heresy.
Because they were living in such a volatile region, the Cappadocian Greeks created elaborate underground cities in the volcanic formations of eastern Cappadocia and would take refuge in them during times of danger.
The Cappadocian Greeks hid in these rock-cut underground towns from many raiders over the next millennium, from 9th century Arab invaders to 11th century Turkish conquerors to 15th century Mongols.
As late as the 20th century the local Cappadocian Greeks were still using the underground cities as refuges (Greek: καταφύγια) from periodic waves of Ottoman persecution.
The most famous of these ancient underground cities are at the Cappadocian Greek villages of Anaku-Inegi (Ανακού) and Malakopi-Melagob (Μαλακοπή).
The Greeks were removed from these villages in 1923, and they are now known as Derinkuyu and Kaymakli.
These underground cities have chambers extending to depths of over 80 meters.

In the Middle Ages Cappadocia had hundreds of settlements and Byzantine rock-cut churches were carved out of the volcanic formations of eastern Cappadocia and decorated with painted icons, Greek writing and decorations.
Over 700 of these Churches have been discovered and date from the period between the 6th century to the 13th century, many of these monasteries and churches continued to be used until the population exchange between Greece and Turkey 1920s.
The Greek inhabitants of these districts of Cappadocia were called Troglodytes.
In the 10th century Leo the Deacon recorded a journey to Cappadocia by Nikephoros Phokas, in his writings he mentions that its inhabitants were called Troglodytes, in view of the fact that they “went underground in holes, clefts and labyrinths, as it were in dens and burrows”.
The Byzantines re-established control of Cappadocia between the 7th and 11th centuries, during this period churches were carved into cliffs and rock faces in the Göreme and Soğanlı region.
In the Middle Ages the Cappadocian Greeks would bury their religious figures in and around monasteries.
In recent years mummified bodies have been found in abandoned Greek monasteries of Cappadocia, and many, including bodies of mummified babies, are on display in the Nigde Archaeological Museum.
A well-preserved mummified corpse of a young Christian woman is popular with tourists; the blonde haired mummy is believed to be a nun and dates from the Byzantine era, from the 6th to the 11th century.
It was discovered in a sixth-century Greek chapel in the Ihlara Valley of Cappadocia.
During the tenth century the Byzantine Empire had pushed east into formerly Arab-ruled lands, including most of Armenia, and had resettled thousands of Armenians into various regions of Cappadocia.
This population shift intensified ethnic tensions between the Cappadocian Greeks and the Armenian newcomers in Cappadocia, and left Armenia largely devoid of native defenders.
By the fifth century the last of the Indo-European native languages of Anatolia ceased to be spoken, replaced by Koine Greek. At the same time the Greek communities of central Anatolia were becoming actively involved in affairs of the Byzantine Empire and some Greek Cappadocians such as Maurice Tiberius (r. 582–602) and Heraclius would even serve as Emperors.
The region became a key Byzantine military district after the advent of Islam and the subsequent Muslim conquest of Syria led to the establishment of a militarized frontier zone (cf kleisoura and thughur) on the border of Cappadocia. This lasted from the mid-7th to the 10th century during the Arab–Byzantine wars, immortalized in Digenis Akritas, the Medieval Greek heroic epic set in this frontier region. During this period Cappadocia became crucial to the empire and produced numerous Byzantine generals, notably the Phokas clan, warlords (see Karbeas of Tephrike), and intrigue, most importantly the Paulician heresy. Because they were living in such a volatile region, the Cappadocian Greeks created elaborate underground cities in the volcanic formations of eastern Cappadocia and would take refuge in them during times of danger. The Cappadocian Greeks hid in these rock-cut underground towns from many raiders over the next millennium, from 9th century Arab invaders to 11th century Turkish conquerors to 15th century Mongols. As late as the 20th century the local Cappadocian Greeks were still using the underground cities as refuges (Greek: καταφύγια) from periodic waves of Ottoman persecution. The most famous of these ancient underground cities are at the Cappadocian Greek villages of Anaku-Inegi (Ανακού) and Malakopi-Melagob (Μαλακοπή). The Greeks were removed from these villages in 1923, and they are now known as Derinkuyu and Kaymakli. These underground cities have chambers extending to depths of over 80 meters.
In the Middle Ages Cappadocia had hundreds of settlements and Byzantine rock-cut churches were carved out of the volcanic formations of eastern Cappadocia and decorated with painted icons, Greek writing and decorations. Over 700 of these Churches have been discovered and date from the period between the 6th century to the 13th century, many of these monasteries and churches continued to be used until the population exchange between Greece and Turkey 1920s. The Greek inhabitants of these districts of Cappadocia were called Troglodytes. In the 10th century Leo the Deacon recorded a journey to Cappadocia by Nikephoros Phokas, in his writings he mentions that its inhabitants were called Troglodytes, in view of the fact that they “went underground in holes, clefts and labyrinths, as it were in dens and burrows”. The Byzantines re-established control of Cappadocia between the 7th and 11th centuries, during this period churches were carved into cliffs and rock faces in the Göreme and Soğanlı region. In the Middle Ages the Cappadocian Greeks would bury their religious figures in and around monasteries. In recent years mummified bodies have been found in abandoned Greek monasteries of Cappadocia, and many, including bodies of mummified babies, are on display in the Nigde Archaeological Museum. A well-preserved mummified corpse of a young Christian woman is popular with tourists; the blonde haired mummy is believed to be a nun and dates from the Byzantine era, from the 6th to the 11th century. It was discovered in a sixth-century Greek chapel in the Ihlara Valley of Cappadocia. During the tenth century the Byzantine Empire had pushed east into formerly Arab-ruled lands, including most of Armenia, and had resettled thousands of Armenians into various regions of Cappadocia. This population shift intensified ethnic tensions between the Cappadocian Greeks and the Armenian newcomers in Cappadocia, and left Armenia largely devoid of native defenders.
Cappadocian Greeks