Ethiopian Orthodox Tewahedo Christianity is one of the world's oldest continuous Christian traditions, established when the Aksumite king Ezana adopted the faith in the 4th century CE. It developed in relative isolation into a distinctive church with its own Ge'ez liturgy, an unusually broad biblical canon, strongly Old Testament–flavored practices, and an identity so fused with Ethiopian nationhood that it survived for centuries as a Christian stronghold amid the spread of Islam.
High in the Ethiopian mountains stands a church carved downward into solid rock, its roof level with the ground around it. To reach it you walk down, not up. Workers cut Bet Giyorgis and the other churches of Lalibela out of the bedrock around the thirteenth century, chiseling whole buildings from the stone. They belong to a Christian tradition that had already been worshipping there for some nine hundred years before the first chisel struck, and that still gathers in them today. It is one of African Christianity's great surviving ancient traditions.