The Auspicious Incident was the forced disbandment of the centuries-old Janissary Corps by Sultan Mahmud II on 15 June 1826. Most of the 135,000 Janissaries revolted against Mahmud II, and after the rebellion was suppressed, most of them were executed, exiled or imprisoned. The disbanded Janissary corps was replaced with a more modern military force.

A janissary was a member of the elite infantry units that formed the Ottoman Sultan's household troops. They were the first modern standing army, and perhaps the first infantry force in the world to be equipped with firearms; adopted during the reign of Murad II. The corps was established either under Sultans Orhan or Murad I, and dismantled by Mahmud II in 1826.