On Tuesday 14th July Dr. M. Yovanovitch, the Serbian Chargé d’Affaires at Berlin, telegraphed to Nikola Pašić, the Prime Minister of Serbia and Minister for Foreign Affairs:
The Secretary of State has told me that he could not understand the provocative attitude of the Serbian press and the attacks made by it against Austria-Hungary, who, as a Great Power, could not tolerate such proceedings.
Nicholas Hartwig was 56 years old when, on 10th July 1914, he paid a call on the Baron Giesl von Gieslingen at the Austro-Hungarian embassy in Belgrade.
Freiherr von Giesl and Hartwig were both ambassadors to Serbia: Baron Nicholas Genrikhovich Hartwig had powerful friends at the Russian court, which had enabled him to take an independent line – he is said to have implied to Serbia that they would get more support from Russia than was official policy, though Russia had for some time been using the Pan Slav idea of unity of Slavs in the Balkan nations to justify aggressive moves against Austro-Hungary or Turkey.
When Baron Hartwig dropped dead from a massive heart attack in the Austro-Hungarian legation, the Serbian press were the first to suspect foul play. Several articles were published accusing the Austrians of poisoning Hartwig while he was visiting their legation.