When Sultan Mehmet IV came to throne, Canakkale Strait (Dardanels) was under the blockade of Venetians. The intrigues in the palace and Celali Revolt were going on. Kosem Sultana and her supporters were very powerful and they were very effective on the administration of the empire. Kosem Sultan decided to poison Sultan Mehmet and replace him with prince Suleyman. But, Turhan Sultana realised this plan, and Kosem Sultan was executed (September 3, 1651).