After the emergence of rival national movements among Balkan Christians, the allegiance of Macedonian Slavs became the apple of discord for nationalists vying for dominion over the region of Macedonia.

Amidst worsening economic and political conditions for Slav peasants, the clandestine Internal Macedonian Revolutionary Organization, founded in 1893, gained a wide following with a program of agrarian reform imposed by terror, culminating in the staging of the Ilinden uprising of 1903, which was swiftly suppressed by the Ottomans.

An armed clash ensued within Slav communities resistant to national proselytization, with IMRO komitadjis fighting against Ottoman authorities and bands of Greek and Serbian nationalists until the pacification imposed after the Young Turk Revolution in 1908.

[2] From the mid-eighteenth till the mid-nineteenth century Greek-, Aromanian- and Albanian-speakers migrated under Albanian pressure from Epirus to Macedonia, forming new villages or settling in Slav-speaking existing ones, and were linguistically assimilated in most cases.

[3] Slavic-speakers, predominating in the rural parts of the region, laboured in Turkish chifliks in the plains or inhabited free mountainous villages and worked as itinerant specialized craftsmen, e.g. builders, across the Balkan peninsula.

Both uprisings were characterized by the absence of concrete planning and demands from the revolutionaries, other than a desire for freedom and putting an end to Muslim rule, and were suppressed in a short time.

[14] Maps and statistics produced mostly reflected their creators' intentions than the demographic reality on the ground, while Ottoman censuses classified their subjects using their religious affiliation further perplexed the issue of their national identity.

[26] Despite the emergence and propagation of national ideologies, the worldview of most Slav peasants in Macedonia was marked by pre-national concerns, and characterized by the fundamental rift between Christian subjects and Muslim overlords.

[27] Towards the end of the nineteenth century living conditions of labourers in the chiftliks deteriorated, after their Turkish owners became indebted to Greek and Jewish merchants and sold their estates.

[29] As prospects of social mobility cultivated by the expanded provision of education were frustrated, a number of teachers and urban professions influenced by socialist ideas formed in 1893 in Salonica a secret revolutionary organization aiming to gain political autonomy for the region of Macedonia.

[34] Having gained a stronghold in the area and having received the promise of Bulgarian intervention, the IMRO staged an anti-Ottoman rebellion, centered around the wealthy free villages of Western Macedonia, on 20 July (O.S.)

[35] The rebellion was brutally suppressed by the Ottomans; tens of villages, mostly in the Manastir Vilayet, were razed to the ground and thousands of uninvolved peasants sought refuge to the mountains.

[citation needed] Moreover, following the Murzsteg Agreement, article 3 of which stipulated the administrative reorganization with a view to a better grouping of different nationalities, the governments of both Greece and Bulgaria began to organize missions of armed nationalist guerrilla bands to Macedonia, composed mostly of Cretans in the Greek case.

[39] Under the pressure of armed nationalist bands, individuals and entire communities in the Slavic-speaking parts of Macedonia were obliged to repeatedly shift their stated national affiliation.

[42] Serbia offered material support to the Ilinden Uprising, and after its suppression, authorities in Belgrade sought but failed to negotiate with Bulgarian leaders on sending Serbian bands into Macedonia for combined action.

A Serbian Committee also had funded small groups of chetniks, either self-organized or part of the Bulgarian revolutionary organizations active in Macedonia (IMRO and SMAC) in spring of 1904.

[50] During the Paris Peace Conference of 1919, the Allies sanctioned Serbian control of Vardar Macedonia and accepted the belief that Macedonian Slavs there were in fact "Southern Serbs".

[52] On February 2, 1925, the Greek parliament, claiming pressure from the Kingdom of Yugoslavia, which threatened to renounce the treaty about the Greek–Serbian Alliance of 1913, refused to ratify the agreement, that lasted until June 10, 1925.