World War One - What Happened?

When the archduke franz ferdinand was assassinated in saraevo, austria hungary blamed serbia for the assassination. The moment this happened, the russians declared war on austro hungary because they were in alliance with serbia. The germans took the opportunity of this war to declare war on france to take back some territory that had been taken from them. And then the germans invaded belgium. There was blood of fighting there. They eventually came into paris. Eventually the italians got involvedh fought the austrians,. strangely enough, even thugh they were part of that triumverat whatever. This was a massively confusing mess