Tengriism

One of the oldest religions in the world, Tengriism is said to have originated sometime in the Bronze Age (between 3600 and 1200 B.C.). Developed by the people of the Altai Mountains in Central Asia, it is a monotheistic religion with heavy elements of ancestor worship. There is no holy book as in other religions and much of the early belief system has fallen out of our collective knowledge. However, it is believed the Huns of the Northern Caucasus may have worshiped a god named Tengri, to whom they were said to have sacrificed horses.
There are a number of close similarities with Christian traditions (as is the case with a lot of “pagan” religions). The most important holiday is known as the Tengrian Epiphany and takes place on December 23. The bulk of that tradition dates back to the fifth century A.D. and involves bringing home a Yule tree and decorating it. While it fell out of popularity during the Mongol era, Tengriism is still practiced to this day—there are even politicians in Kyrgyzstan who are trying to make it the official state religion.