Continuing reverses on the Eastern Front, summer 1915.

Russian Reverses Summer 1915
(adapted from Churchill: The Great War p716) 

This post will take us a bit ahead of ourselves chronologically, but the breakthrough between Gorlice and Tarnow was so profound, that the shock waves reverberated persistently
across the whole conflict. The rapid progress of the Germans over the next four months, represented in the map to the R side of the page, effectively removed the whole of modern Poland from the battle zone, and transformed the huge Polish salient to a more or less straight north - south line. The successive loss of key cities and positions - Warsaw the most significant, on 5th August - is summarised below. 
The impact was far reaching: Germany was able to keep her forces at steady state on the Western Front, in their impregnable defensive positions; she was able to turn resources to the south east to address the rapidly changing situation in the Balkans; Austria was saved, for the moment, from ruin, and was even able to move forces from Galicia to the south to hold off Italy; Russia was exposed even more in the Caucasus by the ongoing failure of the British and French advance on Constantinople via Gallipoli; and the volatile political positions of the neutral Balkan states lurched towards the central powers.

The Russians still had large armies, but were painfully short of munitions and all kinds of supplies. Following Mackensen's breakthrough, the three Russian armies on the Carpathians were forced to retreat towards Lemberg, which itself fell on 22 June. Przemysl had been evacuated on 1 June, after an attempt to defend the river San at Jaroslaw failed.  Germans then turned north, and began an advance to the east of Warsaw, while a second German attack (Twelfth Army), from the north created a pincer that forced the Russians to abandon Warsaw on 5 August. By July Lemberg had been retaken, and Mackensen was poised to strike north to cut the main Russian railway connections. Once more, disputes arose between Falkenhayn at German HQ, and Hindenburg and Ludendorff, in action at the northern end of the German lines. The latter wanted to push further north to capture the main Warsaw to Petrograd rail supply lines beyond Kovno. Falkenhayn had a wider perspective and wished to conserve resources for the Western Front and the Balkans. Both parties gained something from the dispute. Having lost the critical south eastern positions of Przemysl and Lemberg in June and July, the Russians ceded control successively of Warsaw (5^th August); Kovno (10^th); and Novo Georgiesk at the westernmost part of the salient (26^th). On 25 August the key city of Brest-Litovsk fell to the Germans.

By the middle of September the Russians had been forced back to a line that ran from Lithuania south to the Pripet Marshes and the Rumanian border. Russian Poland had been lost, and any direct threat to Germany or to the Austro-Hungarian Empire was gone. Consequent on this dramatic reduction in length of the Eastern Front, Austria found herself no longer under pressure on her Galician border. Conrad was able to transfer large numbers of troops to the south just as Italy was entering the fray. The Italians, instead of the easy gains they had counted upon, soon found themselves pitted against numerous and well prepared Austrian defenders, and entered a stalemate not unlike the Western Front.

Grand Duke Nikolas Nikolaevich 

A million soldiers and civilians were taken prisoner or displaced in Poland in those two months alone. The Russian commander in chief in the west, Grand Duke Nicholas, retreated ahead of his troops and avoided capture. The Grand Duke, uncle to the Tsar - or more correctly his first cousin once removed -  had conducted a skilful retreat and also preserved a large part of the Russian army, but the scale of the defeat led the Tsar to remove him from command and banish him – not to Siberia, but the Caucasus. On 21 August Tsar Nicholas II took direct command of the armies facing west. This established a clear link between the Tsar and progress of the war that would play a significant role in his downfall in the fatal events of 1917.

Tsar Nicholas II -
a dead ringer for his cousin
King George V

These four months represented a great triumph for German miltarism. The only negative element of the campaign from their viewpoint was the growing weakness of their Austro-Hungarian allies, who had lost over one million men since the start of 1915, and were becoming completely dependent on German aid to maintain their war effort. The process that saw the Austro-Hungarian Empire go from being Germany’s (almost) equal ally to being their costly dependent was well under way.