gars removed
to the Balkans; others remained in their native country on the shores of
the Azov Sea, and were subjugated by the Khazars. At the beginning of the
9th century, they marched northwards to the Volga and the Kama, and
established the kingdom of Great Bulgaria. Their chief city, Bolghar, was
on the bank of the Volga, but the river runs now to the west; as the Kama
also underwent a change in its course, it is possible that formerly
Bolghar was built at the junction of the two rivers. (Cf. _Reclus, Europe
russe_, p. 761.) The Bulgars were converted to Islam in 922. Their country
was first invaded by the Mongols under Subutai in 1223; this General
conquered it in 1236, the capital was destroyed the following year, and
the country annexed to the kingdom of Kipchak. Bolghar was again destroyed
in 1391 by Tamerlan. In 1438, Ulugh Mohammed, cousin of Toka Timur,
younger son of Juji, transformed this country into the khanate of Kazan,
which survived till 1552. It had probably been the capital of the Golden
Horde before Sarai.

With reference to the early Christianity of the Bulgarians, to which Yule
refers in his note, the _Laurentian Chronicle_ (A.D. 1229), quoted by
Shpilevsky, adduces evidence to show that in the Great City, i.e.
_Bulgar_, there were Russian Christians and a Christian cemetery, and the
death of a Bulgarian Christian martyr is related in the same chronicle as
well as in the Nikon, Tver, and Tatischef annals in which his name is
given. (Cf. Shpilevsky, _Anc. towns and other Bulgaro-Tartar monuments_,
Kazan, 1877, p. 158 seq.; _Rockhill's Rubruck_, Hakl. Soc. p. 121, note.)
--H. C.]

The severe and lasting winter is spoken of by Ibn Folzan and other old
writers in terms that seem to point to a modern mitigation of climate. It
is remarkable, too, that Ibn Fozlan speaks of the aurora as of very
frequent occurrence, which is not now the case in that latitude. We may
suspect this frequency to have been connected with the greater cold
indicated, and perhaps with a different position of the magnetic pole. Ibn
Fozlan's account of the aurora is very striking:--"Shortly before sunset
the horizon became all very ruddy, and at the same time I heard sounds in
the upper air, with a dull rustling. I looked up and beheld sweeping over
me a fire-red cloud, from which these sounds issued, and in it movements,
as it were, of men and horses; the men grasping bows, lances, and swords.
This I saw, or thought I saw. Then t