What happened between June 1914 and august 1914?

Between June and August 1914, a series of events escalated tensions in Europe, leading to the outbreak of World War I. The assassination of Archduke Franz Ferdinand of Austria on June 28 set off a chain reaction of diplomatic crises. Austria-Hungary issued an ultimatum to Serbia, which, after partial compliance, resulted in Austria-Hungary declaring war on Serbia on July 28. This quickly drew in major powers due to existing alliances, leading to widespread mobilization and the beginning of the war by early August.