Christianity has its origins in Asia. The faith was actually stronger in Asia than most of Europe up until the Islamic conquests of the 600s. While struggling today, the unique and sometimes independent ancient churches of Asia offer a counterpart/complement to the ancient faiths of the Catholic and Orthodox Churches.
Assyrian Church of the East
Assyrian Icon of Christmas from Christians in Iraq
The Assyrian Church of the East has its start with St. Thomas the Apostle. His established the church, headquartered in Babylon, on his journey to India. Before Islam Babylon became a Christian city and the ruling Persian Empire, while Zoroastrian, had a growing Christian minority. The Assyrian Church of the East was part of the "one holy catholic and apostolic Church" along with Rome and Constantinople until 431 over the exact human/divine nature of Jesus. The split was supported by the pagan Persian Empire who sought to divide its Christian subjects from the Church and therefore the Eastern Roman Empire.
There was oppression by the Islamic rulers after the conquest but Sunni versus Shiite battles in present-day Iraq and Iran and rules on "people of the Book" allowed Christians to be ghettoized and left to their own devices. The Assyrian Church expanded into India, Tibet, and China. One of the patriarchs (leader) of the church was Mar Yaballaha III who was a Uyghur born near Beijing. Several attempts to unite with the Catholic Church were made but these deals were either rejected by the bishops or the patriarch was murdered and replaced by the Muslim ruler of the land.
The twentieth-century was one of extremes for the church. Assyrian cooperated with the British during the occupation and paid for it when the nominal pro-British Hashemite monarchy took over Iraq. The situation got so bad that the Patriarch of Babylon was forced to move the churches headquarters to Chicago. The 1990s saw the Roman Church sign agreements with the Assyrians stating the split was over a misunderstanding.
Islamic terrorists have been entering Iraq and a side effect of the violence is that attacks against Christians have increased. Today only about twenty percent of all Assyrians live in their ancient homeland of Iraq.