, believers living on the west coast of India,
the so-called Christians of St Thomas, and finally those belonging to
places nearer the middle of Asia (Merv, Herat, Samarkand), remained in
communion with the Nestorian church. Thus there survived in mid-Asia a
widely-scattered remnant, which, although out of touch with the ancient
usages of Christian civilization, yet in no way lacked higher culture.
Nestorian philosophers and medical practitioners became the teachers of
the great Arabian natural philosophers of the middle ages, and the latter
obtained their knowledge of Greek learning from Syriac translations of the
works of Greek thinkers.

Political conditions at the beginning of the middle ages favoured the
Nestorian church, and the fact that the Arabs had conquered Syria,
Palestine and Egypt, made it possible for her to exert an influence on
the Christians in these countries. Of still more importance was the
brisk commercial intercourse between central Asia and the countries of
the Far East; for this led the Nestorians into China. The inscription of
Si-ngan-fu (before 781) proves a surprisingly widespread extension of
the Christian faith in that country. That it also possessed adherents in
southern Siberia we gather from the inscriptions of Semiryetchensk, and
in the beginning of the 11th century it found its way even into
Mongolia. Nowhere were the nations Christian, but the Christian faith
was everywhere accepted by a not insignificant minority. The foundation
of the Mongolian empire in the beginning of the 13th century did not
disturb the position of the Nestorian church; but the revival of the
Mahommedan power, which was coincident with the downfall of the
Mongolian empire, was pregnant with disaster for her. The greater part
of Nestorian Christendom was now swallowed up by Islam, so that only
remnants of this once extensive church have survived until modern times.

The middle ages were far more disastrous for the Monophysites than for
the Nestorians; in their case there was no alternation of rise and
decline, and we have only a long period of gradual exhaustion to
chronicle. Egypt was the home of Monophysitism, whence it extended also
into Syria. It was due to the great Jacob of Edessa (Jacob Baradaeus, d.
578) that it did not succumb to the persecution by the power of the
Orthodox Empire, and out of gratitude to him the Monophysite Christians
of Syria called themselves _Jacobites_. The Arab conquest (after 635)