An account of the dates and details of the uprising were recorded by the anarchist author Georgi Khadziev which was translated by Will Firth.
On 28 July, the message was sent out to the revolutionary movements, though the secret was kept until the last moment.
The uprising began on the night of August 2, and involved large regions in and around Bitola, around the south-west of what is now North Macedonia and some of the north of Greece.
That night and early the next morning, the town of Kruševo was attacked and captured by 800 rebels.
Concurrently, after three days of fighting followed by a siege starting on August 5, the town of Smilevo was captured by the rebels.
The town of Kleisoura, near Kastoria, was taken by insurgents about August 5.
On August 14, under the leadership of Nikola Pushkarov, some bands near Skopje attacked and derailed a military train.
In Razlog the population joined in the uprising.
This was further east, in Pirin Macedonia in present-day Bulgaria.

On August 4, under leadership of Nikola Karev, a local administration called Kruševo republic had been set up.
That same day and the next, Turkish troops made unsuccessful attempts to retake Kruševo.
On August 12, following the Battle of Sliva, a force of 3,500 Ottoman soldiers recaptured and burned Kruševo.
It had been held by the insurgents for just ten days.
Kleisoura was finally recaptured by the Ottomans on August 27.

Other regions involved included Ohrid, Florina, and Kičevo.
In the Thessaloniki region, operations were much more limited and without much local involvement, due in part to disagreements between the factions of the Internal Macedonian Revolutionary Organization (IMRO).
There was also no uprising in the Prilep area, immediately to the east of Bitola.

The reason why the uprising was strategically chosen in the Bitola vilayet, and the broader southwestern region of Macedonia, was due to the fact that it was located the farthest from Bulgaria, attempting to showcase to the Great Powers that the uprising was purely of a Macedonian character and phenomenon.
Per one of the founders of IMARO — Petar Poparsov the idea to keep distance from Bulgaria, was because any suspicion of its interference could harm both sides: Bulgaria and the organisation.
In fact the uprising soon spread to the adjacent vilayets of Kosovo, Thessaloniki and Adrianople (in Thrace).
An account of the dates and details of the uprising were recorded by the anarchist author Georgi Khadziev which was translated by Will Firth. On 28 July, the message was sent out to the revolutionary movements, though the secret was kept until the last moment. The uprising began on the night of August 2, and involved large regions in and around Bitola, around the south-west of what is now North Macedonia and some of the north of Greece. That night and early the next morning, the town of Kruševo was attacked and captured by 800 rebels. Concurrently, after three days of fighting followed by a siege starting on August 5, the town of Smilevo was captured by the rebels. The town of Kleisoura, near Kastoria, was taken by insurgents about August 5. On August 14, under the leadership of Nikola Pushkarov, some bands near Skopje attacked and derailed a military train. In Razlog the population joined in the uprising. This was further east, in Pirin Macedonia in present-day Bulgaria. 
On August 4, under leadership of Nikola Karev, a local administration called Kruševo republic had been set up. That same day and the next, Turkish troops made unsuccessful attempts to retake Kruševo. On August 12, following the Battle of Sliva, a force of 3,500 Ottoman soldiers recaptured and burned Kruševo. It had been held by the insurgents for just ten days. Kleisoura was finally recaptured by the Ottomans on August 27.
Other regions involved included Ohrid, Florina, and Kičevo. In the Thessaloniki region, operations were much more limited and without much local involvement, due in part to disagreements between the factions of the Internal Macedonian Revolutionary Organization (IMRO). There was also no uprising in the Prilep area, immediately to the east of Bitola.
The reason why the uprising was strategically chosen in the Bitola vilayet, and the broader southwestern region of Macedonia, was due to the fact that it was located the farthest from Bulgaria, attempting to showcase to the Great Powers that the uprising was purely of a Macedonian character and phenomenon. Per one of the founders of IMARO — Petar Poparsov the idea to keep distance from Bulgaria, was because any suspicion of its interference could harm both sides: Bulgaria and the organisation. In fact the uprising soon spread to the adjacent vilayets of Kosovo, Thessaloniki and Adrianople (in Thrace).
Ilinden–Preobrazhenie Uprising