December 19, 1918 
LAND & WATER 
(e) The over-running of Poland and Serbia. 
The preparation for this great effort had occupied all the 
later winter ci 1 914-15, and by the end of April everything 
was ready for its inception. 
The principle upoff which the attack was based was the 
concentration of an hitherto unknown mass of artillery, to 
" blast through " the siege lines by such an overwhelming 
weight of fire as warfare had never 
seen — something a hundredfold 
greater than other bombardments. 
This conception was furthered by 
the corresponding^weakness of the 
defensive to which it was opposed. 
Under the unexampled concen- 
tration of artillery drawn up 
between the Carpathitms and the 
Upper Vistula in front oftCracow 
(the sector which had been chosen 
for the effort) the Russians had 
but a few heavy guns and were 
provided with a stock of ammuni- 
tion wholly inadequate to the 
task of defence. As the campaign 
proceeded this handicap grew 
more and more severe, until by 
the end of the summer many of 
the Russian units lacked even 
rifles and were captured armed 
with clubs alone,'' while for many 
batteries shell failed altogether. 
Behind this immense concen- 
tration of artillery the Germans 
and Austrians had created under 
the command of Mackensen what 
they called a "phalanx " — that is 
a very dense body of men capable 
of supply only by a main railway 
(along which they marched), and 
destined to utilise the breach 
which artillery would effect. It 
was upon the last day of April, 
1 915, that this formidable new instrument of warfare struck 
its blow, and upon May ist its success was complete. 
The lines between the Upper Vistula and the Carpathians, 
which are known as the Lines of Gorlice, were completely 
breached, fnd an extrem ly rapid advance of the phalanx 
followed. The Russians fell back with very heavy loss of men 
and guns, first to the line of the San, then further eastward to- 
wards Lemberg.Jand to the south 
towards their own frontier, while 
in the north a corresponding 
movement to keep the line, neces- 
sitated the retirement ever where 
upon the Vistula 
It was the singular feature of 
this continuous Austro-German 
advance which, during the sum- 
mer of 1 915, completely over-ran 
Poland, that in spite of Russia's 
growing^weakness and the des- 
perate lack of weapons, the siege 
was not, in the full strategical 
sense of the term, raised. In 
other words, though the Russian 
Army fell back two hundred miles 
and though, when, in the accurate 
words of Lord Kitchener, the 
enemy had " shot his bolt," by the 
end of the summer he held a line 
stretching from near Riga right 
away to the Roumanian frontier 
and even occupied posts through 
the Pripet marshes covering Brest, 
yet he still had in front of him 
intact, though deplorably weak- 
ened, a siege line. 
As it later turned out, the effect 
of the great German and Austrian 
advance over Poland was political. 
Meanwhile in the September of 
that year, while the last successes 
of Germany and Austria were 
b ing won upon the Polish field, England and France attempted, 
by two converging attacks, to effect a breach in the Western 
line. They had studied the lessons of the enemy successes 
in front ofiCracow. They in turn massed artillery upon a 
scale hit' erto undreamed of by them, and upon September 
25th, 1915, the French upon one side of the great German 
salient in Northern France, in Chamjjagne, the British 
upon the other side above La Bassee delivered the heaviest 
GENERAL SIR WILLIAM BIRDWOOD 
GENERAL DIAZ 
blow of which they were then capable. Neither succeeded. The 
French double effort, though costing the enemy a heavy loss 
in prisoners and guns, though shaking him for the moment, and 
until it was better studied and understood, promising further 
development, actually failed. ^No breach was effected and the 
incident in the long run increased the prestige of the modern 
defensive in general, and of our enemy's in particular. They 
had held ; and while they thus held 
in the West, they stood though 
still faced by siege lines , complete 
masters of Poland. 
The losses of these myriads of 
prisoners, of these thousands of 
guns, the shame of the retreat 
and its appalling expense in life 
and prestige, profoundly shook 
the structure of the Russian 
State, and was to produce within 
eighteen months the disintegra- 
tion of that society. But at any 
rate, for the moment the siege 
lines, though so profoundly modi- 
fied upon the East, still held. By 
the end of the summer one could 
say that as a sortie the Eastern 
effort had not succeeded. But as 
a modification of siege conditions 
it had largely succeeded. It 
raised the moral of the enemy 
to the highest pitch through a 
succession of victories. An at- 
tempt to renew siege-pressure 
from the East was hardly to be 
expected. It subjected to German 
direction all those Slavonic ele- 
ments of the Eastern marches 
which were the hereditary pre- 
occupation of the Prussian House. 
It acquired for the besieged new 
stores of supply and particularly 
• the petroleum ofJGalicia. 
Meanwhile, just at the moment when the breaking of the 
Allies between the Vistula and the Carpathians was producing 
its effect, within two months of the original blow being de- 
livered, Italy, hitherto neutral, joined the forces of the Allies. 
This accession of strength was some compensation for the 
draining of the forces of Russia. It brought back from the 
East to the defence of the Alpine frontiers perhaps a third, 
perhaps more than a third, of the 
Austro-Hungarian armies, and the 
pressure to be maintained here 
for three years absorbed more and 
more of the Austro-Hungarian 
forces as time went on, until 
towards the close of the war 
nearly all the remaining strength 
of the Austro-Hungarians was 
massed between the Swiss frontier 
and the Adriatic. The great 
advance through Poland had for 
its climax and termination the 
overrunning of Serbia and Mon- 
tenegro. Serbia had hitherto 
met with singular success in the 
attack of the Austro-Hungarian 
armies. The first invasion at the 
outset of the war had been thrown 
back] and no attempt to renew it 
had been made, but now, with larg- 
er and better trained forces, and 
with a considerable admixture of 
German divisions, the attempt 
was renewed, and was the more 
successful from the fact that the 
King of Bulgaria, hitherto neutral, 
seized the opportunity to join the 
central armies, attack Serbia in 
flank and completed the tem- 
porary ruin of that country. It 
is clear that so sudden and com- 
plete a success in the Serbian 
field threatened two things, first 
the access of the enemy to the ^Egean with all that this would 
have meant in the use of submarines over the Levant, and 
secondly the persuasion of Greece, the King of which country 
was closely allied by marriage to Prussia, and was also a con- 
vinced admirer of the Prussian system, to join the Central 
Empires. To prevcnt^either of these disasters the Allies, with 
such expedition s they could, attempted to check the enemy 
advance southward through the Balkan . They seized the 
