23. The Black Hand
This group was composed of 10 men from Serbia who used violence and terrorist activities to create a divide in Serbia. This group was formed in 1901 by some of the officers in the army of the kingdom of Serbia.
This group is most known for their attempted assassination of Archduke Franz Fernidad during his motorcade, which was not successful. In 1903, this group’s leader instructed a coup, which brought King Petar Karadordevic to the Serbian throne 45 years later.