Serbia had recently gained complete independence from the Ottoman Empire. Some Serbs longed for a return to the good old days of the Serbian Empire of the Middle Ages. There were ethnic Serbs living in the neighboring Austro-Hungarian Empire. The Pan-Serbian nationalists wanted these Serbs, and the land they lived on, from the Austro-Hungarian Empire and added to Serbia.
The Emperor of Austro-Hungary was old. His heir would soon inherit the throne. The heir showed signs of being a reformer. The Pan-Serbians feared that, once on the throne, the heir would be so accommodating to the ethnic Serbs in his Empire that they would lose any desire to get out of the Empire and unite with Serbia. So, they murdered the heir, which was the spark the set off WWI.
There was no way Serbia could avoid Yugoslav war, because if there was Serbia would have done it...
Serbia Serbia
Serbia was in WWI because Austria-Hungary declared war on them.
When Russia found out that Austria-Hungary was declaring war on Serbia, they came into alliance with Serbia for several reasons.
The Archduke of Austria Franz Ferdinand was assassinated by a Bosnian-Serb. In retaliation Austria-Hungary gave Serbia an Ultimatum of demands designed to destroy Serbia's influence in Bosnia. Serbia rejected the Ultimatum and Austria-Hungary declared war on Serbia. Germany was Austria-Hungary's ally and agreed to assist Austria-Hungary in the invasion of Serbia. Russia, fearing an invasion of Serbia would end it's own influence in the Balkans began to mobilize for war. As a result, Germany declared war on Russia.
No, Serbia was not part of Russia during World War 1. Serbia was an independent country that was allied with Russia during the war.
The 1st country to declare war on Serbia was Austria-Hungary.
as Bilbo was wanting to make peace so there is no war
The war between Serbia and Kosovo was going on. The war started because Serbia wanted more territory from Kosovo.
Austria-hungary attacked Serbia
Russia
At the begining of the war Serbia was allied with Montenegro, Russia and Greece. Greece stayed neutral in war, while Montenegro and Russia helped Serbia to fight with Austria-Hungary. When Serbo-Austrian war became World war Serbia alongside Russia and MOntenegro was part of Entante (Allies).