Cappadocia has been home to various civilizations throughout history, including the Hittites, Persians, and Romans. The Hittites established a powerful kingdom in the region in the 2nd millennium BC. Later, the Persians ruled Cappadocia before it became part of the Roman Empire. During the Roman and Byzantine periods, Cappadocia became an important center of early Christianity. The region's unique rock formations provided ideal hiding places for early Christians fleeing persecution. Many rock-cut churches and monasteries were carved into the soft volcanic rock, some of which still survive today, adorned with beautiful Byzantine frescoes.