Austria-Hungary declares war on Serbia

On 28 July 1914, exactly a month after the assassination in Sarajevo, Austria-Hungary declared war on Serbia. That same night the first shells fell on Belgrade. For many historians this day marks the beginning of the First World War. A conflict that Vienna had wanted to confine to a short reckoning with its neighbour drew all the great powers of Europe into war within a week.

War declared by telegram

The decision was approved by Emperor Franz Joseph I, who was still at his summer residence in Bad Ischl. Because diplomatic relations with Serbia had been broken off three days earlier, there was no longer an Austro-Hungarian minister in Belgrade to deliver a note. Foreign Minister Leopold Berchtold therefore sent a telegram from Vienna at 11:10 a.m. to the Serbian prime minister, Nikola Pašić.

The message, written in French, went over the ordinary telegraph network via Bucharest as open, unencrypted text. It reached Niš, where the Serbian government had moved, at about 12:30 p.m. In it Berchtold declared that the Serbian government had not given a satisfactory reply to the note of 23 July, and that the monarchy accordingly considered itself to be in a state of war with Serbia. It was the first time in history that war had been declared by telegram. The unusual form led Pašić at first to suspect a hoax and to seek confirmation that the document was genuine.

The telegram concerned only Austria-Hungary and Serbia. It made no mention of Russia, Germany, France or Great Britain, which reflects Vienna’s hope that the war would remain local. Today it is inscribed on UNESCO’s Memory of the World register as one of the most important documents of the twentieth century.

A chance that was missed

That same morning Kaiser Wilhelm II, only just back from Norway, read the full text of the Serbian reply to the ultimatum for the first time. He judged it a great moral victory for Vienna and declared that every reason for war had fallen away. He proposed that Austria-Hungary should merely occupy Belgrade as a pledge and stop there, settling the rest of the dispute through negotiation.

Chancellor Theobald von Bethmann Hollweg, however, passed the proposal on to Vienna only late in the evening and in a watered-down form. By the time it arrived, war had already been declared. It was one of the last moments when a decision by one of the powers could still have halted the course of events.

The first shots

On the night of 28–29 July Austro-Hungarian artillery positioned in Zemun and river monitors on the Danube and the Sava shelled Belgrade. The shells struck, among other places, a school, the Grand Hotel, cafés and banks. The Serbian capital, lying right on the border, found itself on the front line from the first hours of the war. On 28 July Franz Joseph also signed the manifesto “To My Peoples”, in which he explained to his subjects why the monarchy had taken up arms.

The actual advance of troops into Serbia had to wait for mobilisation to be completed, and its first day was 28 July itself. The Serbian campaign began in earnest only in mid-August.

From a local war to a world war

Vienna had counted on the war with Serbia being short and local. It turned out otherwise, because behind Serbia stood Russia, and behind Austria-Hungary stood Germany. Over the following days Russia announced mobilisation, and Germany responded by declaring war on Russia on 1 August and on France on 3 August. On 4 August, after the German invasion of Belgium, Great Britain entered the war.

A single week was thus enough for a local conflict in the Balkans to turn into a general European war, and soon a world war. That is why 28 July 1914 is one of the most important dates in the history of Europe. The telegram sent from Vienna to Niš opened a war that lasted more than four years, claimed millions of lives and redrew the map of the continent.