Original sentence: The July Crisis was a diplomatic crisis among the major powers of Europe in the summer of 1914 that led to the First World War, immediately after the assassination of Archduke Franz Ferdinand, heir to the Austro-Hungarian throne, in Sarajevo, Bosnia, by Gavrilo Princip, a Yugoslav (ethnic Serb) nationalist
Edited sentence: It followed a campaign of several years by agents of the Kingdom of Serbia to destabilize Austro-Hungarian control over Bosnia.The July Crisis was a diplomatic crisis among the major powers of Europe in the summer of 1914 that led to the First World War.The immediate occasion of the crisis was the assassination of Archduke Franz Ferdinand, heir to the Austro-Hungarian throne, in Sarajevo, Bosnia, by Gavrilo Princip, a Yugoslav (ethnic Serb) nationalist