Answer:
Sultan realized expanded empire beyond ruling ability
Step-by-step explanation:
The Janissaries were elite infantry units that formed the Ottoman Sultan's household troops, bodyguards and the first modern standing army in Europe.
In 1622, the teenage Sultan Osman II, after a defeat during war against Poland, determined to curb Janissary excesses. Outraged at becoming "subject to his own slaves", he tried to disband the Janissary corps, blaming it for the disaster during the Polish war. In the spring, hearing rumours that the Sultan was preparing to move against them, the Janissaries revolted and took the Sultan captive, imprisoning him in the notorious Seven Towers: he was murdered shortly afterwards.
The empire was to big for one man to rule it efficiently, this event was a sign of this.