re a certain John,
inhabiting the extreme East, king and Nestorian priest, and claiming
descent from the Three Wise Kings, had made war on the _Samiard_ Kings of
the Medes and Persians, and had taken Ecbatana their capital. He was then
proceeding to the deliverance of Jerusalem, but was stopped by the Tigris,
which he could not cross, and compelled by disease in his host to retire.

M. d'Avezac first showed to whom this account must apply, and the subject
has more recently been set forth with great completeness and learning by
Dr. Gustavus Oppert. The conqueror in question was the founder of Kara
Khitai, which existed as a great Empire in Asia during the last two-thirds
of the 12th century. This chief was a prince of the Khitan dynasty of
Liao, who escaped with a body of followers from Northern China on the
overthrow of that dynasty by the _Kin_ or Niuchen about 1125. He is called
by the Chinese historians Yeliu Tashi; by Abulghazi, Nuzi Taigri Ili; and
by Rashiduddin, Nushi (or Fushi) Taifu. Being well received by the Uighurs
and other tribes west of the Desert who had been subject to the Khitan
Empire, he gathered an army and commenced a course of conquest which
eventually extended over Eastern and Western Turkestan, including
Khwarizm, which became tributary to him. He took the title of _Gurkhan_,
said to mean Universal or Suzerain Khan, and fixed at Bala Sagun, north of
the Thian Shan, the capital of his Empire, which became known as _Kara_
(Black) _Khitai_.[1] [The dynasty being named by the Chinese _Si-Liao_
(Western Liao) lasted till it was destroyed in 1218.--H. C.] In 1141 he
came to the aid of the King of Khwarizm against _Sanjar_ the Seljukian
sovereign of Persia (whence the _Samiard_ of the Syrian Bishop), who had
just taken Samarkand, and defeated that prince with great slaughter.
Though the Gurkhan himself is not described to have extended his conquests
into Persia, the King of Khwarizm followed up the victory by an invasion
of that country, in which he plundered the treasury and cities of Sanjar.

Admitting this Karacathayan prince to be the first conqueror (in Asia, at
all events) to whom the name of Prester John was applied, it still remains
obscure how that name arose. Oppert supposes that _Gurkhan_ or _Kurkhan_,
softened in West Turkish pronunciation into _Yurkan_, was confounded with
_Yochanan_ or _Johannes_; but he finds no evidence of the conqueror's
profession of Christianity except the fact, notab