Internal Macedonian Revolutionary Organization

The organisation modelled itself on Vasil Levski's Bulgarian Internal Revolutionary Organization and took up the motto "Freedom or Death". Its 1894 statute restricted membership to Bulgarians, but Gotse Delchev, under the slogan "Macedonia for the Macedonians", opened it to all inhabitants of European Turkey. Other groups still saw it as "the Bulgarian Committee", and its base remained among Slavic speakers of the Bulgarian millet. In the Ilinden-Preobrazhenie Uprising of August 1903 some 15,000 irregulars fought 40,000 Ottoman soldiers for over seven weeks, and the suppression destroyed about 100 villages.

After the failure the organisation split between a left-wing federalist faction, favouring autonomy and a future Balkan federation and led by socialist-inspired figures such as Yane Sandanski and Hristo Chernopeev, and a right-wing centralist faction that wanted union with Bulgaria. After the Young Turk Revolution of 1908 both laid down their arms for legal politics. In the Balkan Wars former leaders of both wings joined the Macedonian-Adrianopolitan Volunteer Corps and fought with the Bulgarian army, and during the second war the organisation raised the Tikvesh Uprising against Serbian occupation. Its adherents saw the division of the region not as "liberation" but as the partition of Macedonia. English Wikipedia judges that it later became an agent serving Bulgarian interests. After years of interwar assassinations, it was suppressed by the army following the Bulgarian military coup of 19 May 1934 and ceased to be an active political force.