Jeff Yu said:
The earliest Europeans in China were the Jesuits from Portugal, who attempted to spread Christianity into China.
WHAT - that is completley wrong.
Wiki to the rescue again ... Nestorianism is a christian heresy (but christian) and they originated from europe - Constantinople -> Nestorius
They got to china, koreea, mongolia a loooooong time before the jesuits even were formed.
http://en.wikipedia.org/wiki/Nestorian
The spread of "Nestorianism"
The Assyrian Church produced many zealous missionaries, who traveled and preached throughout Persia and Central and East Asia in the seventh and eighth centuries. Also during this time many Nestorian scholars, having escaped the Byzantines, settled in Gundishapur, Persia, and brought with them many ancient Greco-Roman philosophical, scientific and literary texts. "Nestorian" Christianity reached China by 635, and its relics can still be seen in Chinese cities such as Xi'an. About the same time Nestorian Christianity penetrated into Mongolia, eventually reaching as far as Korea. The Nestorian Stele, set up on 7 January 781 at the then-capital of Chang'an, describes the introduction of Christianity into China from Persia in the reign of Tang Taizong.
The Christian community later faced persecution from Emperor Tang Wu Zong (reigned 840-846). He suppressed all foreign religions, including Buddhism and Christianity, which then declined sharply in China. A Syrian monk visiting China a few decades later described many churches in ruin. The Church experienced a significant revival during the Yuan dynasty. Marco Polo in the 1200s and other medieval Western writers indicate many Nestorian communities remaining in China and Mongolia; however, they clearly were not as vibrant as they had been during Tang times. The communities seem to have petered out due to hostility from the Ming dynasty. The legacy of the missionaries remains in the Assyrian churches still to be found in Iraq, Iran, and India.