Balkan Theatre
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The Balkan Theatre of the Great War was fought primarily between the Russian and Ottoman Empires. After the first few months of the European conflict, the Ottoman Empire was drawn into the fight, where it bombarded Italian positions in Tunis and Dalmatia. This resulted in Italy calling upon its alliance with Russia under the terms of the Berlin Treaty.
In response, Russia - already fighting on two fronts - opened up a third front in the Balkans, as it moved its troops southward from Wallachia in July of 1906. As the Russians moved in, unrest in the Ottoman-occupied Balkans overflowed into revolution, as many of the regions declared independence. As Ottoman garrisons were redirected from these areas to slow the Russian advance or driven out by the insurgents, these regions were able to consolidate their independence.
Once their independence was secured, they joined with Russia and the other independent nations of the Balkans (Serbia, Montenegro, Romania and Greece) in pushing back the Ottomans. The number of insurgencies, combined with the sheer number of incoming soldiers, made the construction of trenches for the Ottomans nigh-impossible, at least until they were pushed back to Thrace.
As the Russians and their allies began moving in on Constantinople in mid-1908, the advance slowed down to a crawl. With the land forming a bottleneck, and with no more insurgencies or rebellions to handle, the Ottoman forces were able to halt the Russian advance by December of 1908 - 35 kilometres from Constantinople. However, in order to gather the manpower needed to stop the Russians, the Ottomans were forced to withdraw their troops from the European Theater, as well as pull back their ships from the Atlantic.
The frontline of the Balkan war became much like that of the war between the Germans and French - a mess of blood-stained trenches, lined with machine-guns and barbed wire. The line went from advancing a few kilometres on a daily basis to advancing three or four kilometres a month, at the cost of an average of four thousand troops a day. Naval strikes on the Ottoman front-line by the Black Sea Fleet were becoming a regular occurance, and air attacks on Constantinople were also carried out.
Eventually, by August of 1909, the Russians had forced the Ottomans back all the way to Constantinople, where they began to lay siege to the city. Tired of the war of attrition with Russia, and their allies also overstretched fighting Germany and Italy in Europe, the Ottomans surrendered in less than three months; the ceasefire between themselves and the Russians took effect at roughly the same time as the ceasefire in the west. The Ottomans joined negotiations with the other European powers in order to establish the terms of the armistice.