The Eastern Orthodox Faith was established in the year 33 AD by Jesus Christ on the Day of Pentecost in Jerusalem. From there it spread to most of the world, from places like Greece, Antioch, Europe, Russia, Africa, America, etc.
Your question is strangely asked.
The word "orthodox" is based on the Greek words "orthos" meaning right, true, straight, and "doxa" meaning praise. The word then refers to something which is the "right idea."
Those who hold to what may be called "traditional Christianity" (the faith of the early Church as described in the New Testament) are considered to be "orthodox" in their beliefs.
One of the three major branches of Christianity is common described as the "Orthodox Church" as opposed to Roman Catholic and Protestant branches.
orthodox Christianity
Eastern Orthodox Christianity. Though there are a small amount of born-again Christians, Jewish people, and Muslims in Russia.
Orthodox Christianity.
It was Orthodox Christianity.
Islam and Catholic/Orthodox Christianity.
The Greek Orthodox regard themselves as the Original Christianity.
Orthodox Christianity
Orthodox Christianity.
Greek Orthodox is a denomination in Christianity.
Eastern Orthodox is a branch of Christianity.
Christianity
Russian Orthodox,or Orthodox Christianity,both mean the same thing :)