Bulgarian guerrillas in Macedonia

Since 1899, Bulgarian guerrillas in Macedonia (the Internal Macedonian-Adrianople Revolutionary Organization, commonly known by the abreviation VMRO) turned against Turkish authorities with the slogan "autonomy for Macedonia". The guerrillas agitated under the auspices of officers of the Bulgarian army, and purported to be protectors of all Christians in the area. For this reason they initially they did not bother Greece. But gradually, their real intentions became clear after the assassinations of members of pro-Greek and pro-Serbian parties.

The situation became heated in Macedonia and started to affect Greek, Serbian and European public opinion. In April 1903, a group of anarchists with some assistance from the VMRO blew up the French ship "Guadalquivir" and the Ottoman Bank in the harbour of Thessaloniki. In August 1903, the Bulgarian VMRO managed to organise an uprising (the Ilinden-Preobrazhenie Uprising) in Macedonia and the Adrianople Vilayet. The insurrection proved to be unsuccessful and was eventually suppressed by the Ottomans with the subsequent destruction of many villages and the devastation of large areas in Western Macedonia and around Kirk-Klisse near Adrianople.

In Athens, nationalist organisations organised demonstrations against Bulgaria, but the official Greek State, numbed from the defeat of 1897 hesitated over what to do.The Greek Embassy in Thessaloniki became the centre of the struggle, coordinating the guerrilla troops, distributing of military material and nursing wounded. Fierce conflicts between the Greeks and Bulgarians started in the area of Kastoria (Kostur), in the Giannitsa Lake and elsewhere; both parties committed cruel crimes at points. The greatest bloodshed was the massacre in the village Zagorichani (predomintantly populated by Bulgarians) in Kastoria district in 1905 when 79 Bulgarian inhabitants were executed.

The guerilla groups were also hunted by the Turkish Army. These conflicts ended after the revolution of "Young Turks" in July, 1908, as they promised to respect all ethnicities and religions and generally to provide a constitution.