retenders induced him to go so far as to forbid
the greatest of the boyars to marry. He also encouraged informers and
persecuted suspects on their unsupported statements. The Romanov family
in especial suffered severely from these delations. Boris died suddenly
(April 13, 1605), leaving one son, Theodore II., who succeeded him for a
few months and then was foully murdered by the enemies of the Godunovs.

See Platon Vasilievich Pavlov, _On the Historical Significance of the
Reign of Boris Godunov_ (Rus.) (Moscow, 1850); Sergyei Mikhailivich
Solovev, _History of Russia_ (Rus.) (2nd ed., vols. vii.-viii., St
Petersburg, 1897). (R. N. B.)

BORISOGLYEBSK, a town of Russia, in the government of Tambov, 100 m.
S.S.E. of the city of that name, in 51 deg. 22' N. lat. and 43 deg. 4'
E. long. It was founded in 1646 to defend the southern frontiers of
Muscovy against the Crimean Tatars, and in 1696 was surrounded by wooden
fortifications. The principal industries are the preparation of wool,
iron-casting, soap-boiling, tallow-melting, and brick-making; and there
is an active trade in grain, wool, cattle, and leather, and two
important annual fairs. Pop. (1867) 12,254; (1897) 22,370.

BORKU, or BORGU, a region of Central Africa between 17 deg. and 19 deg.
N. and 18 deg. and 21 deg. E., forming part of the transitional zone
between the arid wastes of the Sahara and the fertile lands of the
central Sudan. It is bounded N. by the Tibesti Mountains, and is in
great measure occupied by lesser elevations belonging to the same
system. These hills to the south and east merge into the plains of Wadai
and Darfur. South-west, in the direction of Lake Chad, is the Bodele
basin. The drainage of the country is to the lake, but the numerous
khors with which its surface is scored are mostly dry or contain water
for brief periods only. A considerable part of the soil is light sand
drifted about by the wind. The irrigated and fertile portions consist
mainly of a number of valleys separated from each other by low and
irregular limestone rocks. They furnish excellent dates. Barley is also
cultivated. The northern valleys are inhabited by a settled population
of Tibbu stock, known as the Daza, and by colonies of negroes; the
others are mainly visited by nomadic Berber and Arab tribes. The
inhabitants own large numbers of goats and asses.

A caravan route from Barca and the Kufra oasis passes through Borku to
Lake Chad. The cou