ld of the Austro-Serbian battles.

A description of this section, in brief at least, is necessary to an
understanding of the three Austrian invasions made here, and all three
of which failed disastrously. North and west of Shabatz lies the great
plain of Matchva, bounded on its east and north by the Save and by the
Drina on the west. It is a rich, fertile land, but much broken up by
woodland. To the southeast a rolling valley is divided by the River
Dobrava, while due south the Tzer Mountains rise like a camel's back out
of the plain and stretch right across from the Drina to the Dobrava. The
southern slopes of Tzer are less abrupt than those on the north and
descend gradually into the Leschnitza Valley, out of which rise the
lesser heights of the Iverak Mountains. Both these ranges are largely
covered by prune orchards, intersected with some sparse timber.

This is a region of natural fortifications. Descending southward again,
the foothills of Iverak are lost in a chain of summits, which flank the
right bank of the Jadar River, that tributary of the Drina River from
which the first big battle takes its name.

From the left bank of the Jadar, from its junction with the Drina to
Jarebitze, a great rolling level stretches south until the high Guchevo
Mountains, stretching in southeasterly direction, rise abruptly and hide
the Bosnian hills from view. From there, southward, the country is
extremely mountainous, even the highways being blasted out of the sides
of the precipitous mountains along the innumerable ravines through which
run watercourses which, though almost dry in summer, burst into
torrential streams after the snows begin to melt in the higher
altitudes.

Naturally in such a country roads are of prime importance in military
operations. A few built and maintained by the state are in excellent
condition and practicable in all sorts of weather. But for the rest
communications consist of bridle paths and trails over the mountains.

As has been stated, the great highway from Belgrade to Saloniki is the
key to all military operations in the Balkans; nor is this case any
exception. A study of the map will show how this big, underlying fact
entered into the plans of the first three attempts at invading Serbia.
Naturally, had facilities been convenient at Belgrade, that would have
been the point from which to advance. The next possible point was over
the Drina, because it was not so wide or so deep.

Bosnia and H