Prehistory and antiquity From traces of settlement it is known that the region of Cappadocia was inhabited in prehistoric times. Whether rock-cuttings had already been made at that time is not clear. It is probable that in the
Bronze Age at the latest, when the region was in the middle of the
Hittite empire, the first passageways and rooms had been cut into the rock, as well as reservoirs and possibly even refuges in the cliffs. In
Derinkuyu underground city, only one tool of Hittite origin has been found and it might have been brought there at a later date. The earliest attestation of these structures is in
Xenophon's
Anabasis, which mentions people in Anatolia who had built their houses underground.
Christian settlement The initial
Christian settlement of the region came in the first centuries AD, starting with
hermits who retreated into the seclusion of the tough landscape from the Christian community at
Caesarea. They either settled in caves that already existed or dug their own residences in the cliffs. Since they were seeking solitude rather than protection from enemies, they largely made their homes above ground level. After the Christian church was re-organised under the
Cappadocian Fathers (
Basil of Caesarea,
Gregory of Nyssa, and
Gregory of Nazianzus) in the fourth century AD, ever larger groups of Christians followed them over the next few centuries, settling in Cappadocia and building cloistered communities, which meant that they needed ever more and ever larger residential and religious spaces. Meanwhile, in the fourth century, the
Isaurians invaded, in the fifth century the
Huns, and finally in the sixth century the
Sassanid Persians; in 605 the city of Caesarea was conquered during the
Byzantine–Sasanian War of 602–628. These incursions sparked the intensive construction of rock-cut buildings below and above ground, including whole cities. The design of these structures was principally shaped by security and defensive concerns. From 642, the
Arabs began to invade the region and these concerns grew increasingly significant, with the result that Christian communities continued to live in the region for three centuries, secure from raids. Eventually, the
Byzantines regained control over
Cappadocia and under their rule Christianity and Christian architecture in Cappadocia entered a golden age. By the eleventh century, roughly three thousand churches had been carved in the rocks. . In the
Battle of Manzikert in 1071, the
Seljuk Sultan
Alp Arslan defeated the Byzantine Emperor
Romanos IV, marking the end of Byzantine rule in Anatolia and the beginning of Turkish pre-eminence in the region. Despite the religious tolerance of the Seljuks, this marked the beginning of the decline of Christianity in Cappadocia and the long decline of church architecture. As a result of the gradual emigration of the Christian inhabitants, the existing cloisters were slowly taken over by Turkish farmers, who renovated them according to their own needs. Since camouflage and defence were no longer necessary, facades and houses were built in front of entranceways that had formerly been hidden and inconspicuous. The rock-cut houses continued to be used by the Turkish inhabitants in the twentieth century – partially because of the continuously pleasant temperatures under the rock. In 1832, the population had to make use of the underground cities for safety against Egyptian armies during the
First Egyptian-Ottoman War. The last remaining Christians left the area in 1923 as part of the
population exchange between Greece and Turkey. The final Turkish inhabitants moved out of the cave settlement at
Zelve in the 1950s after earthquakes had done significant damage and made the structures increasingly dangerous. Even today, some caves in
Uçhisar,
Ortahisar, and the
Soğanlı valley are still used, at least during the hot summer months, usually with a house attached to them. == Underground cities ==