It had been exactly one month since the death of Archduke, Franz Ferdinand, and his beloved wife Sophie, Duchess Von Hohenberg. Since then the assassination Prince has been jailed for his crimes, but this is still not enough for the Austro- Hungarian’s so they sent the ultimatum to be able to get the rest of the people involved and the black hand. Knowing that they had allies with the Germans and with an agreement of Berlin the ultimate was sent to Serbia on July 23, 1914. It simply stated that to let the Austro- Hungarian authorities to have safe passage in the country of Serbia to apprehend the members of the black hand and anyone in the involved with the assassination. There was a demand to be answered in 48 hours. This did not go the way the Austro- Hungarian wanted, the Serbian instead of cooperating with the request refused when to Russia for military help. The Austro- Hungarian took this matter to heart and on July 25th, 1914 the Austro- Hungarian began to mobilize their troops. The Serbians got note of this and as well got their troop in motion. Today, July 28th, 1914 Austria – Hungary has officially declared war on Serbia, and so the great war has begun.
References :
http://www.history.com/this-day-in-history/austria-hungary-issues-ultimatum-to-serbia