Most historians recognize that the assassination of Austria's Archduke Franz Ferdinand in June 1914 was the event that fueled what would become known as World War I. As the future leader of Austria-Hungary, Ferdinand's murder by a Yugoslavian (Bosnian, Serbian) assassin led to a series of demands made by Austria-Hungary to Serbia. Although Serbia agreed to eight of the 10 conditions of the July Ultimatum, the Austro-Hungarian Empire declared war against the Kingdom of Serbia and invaded Serbia a month later. Due to longstanding political allegiances, Austria-Hungary's ally, Germany, soon invaded France, Belgium and Luxembourg. Russia, an ally of Serbia, then attacked Germany. The Ottoman Empire (comprised primarily of what is now Turkey) soon joined the Central Powers, while Britain joined the Allies later that year, followed by Italy in 1915.