Alemdar Mustafa Pasha and his supporters were planing to ascend Sultan Selim III again. They organised an army consisted of 16.000.000 soldiers, Alemdar Pasha sent Haci Ali Aga to Istanbul and killed Kabakci Mustafa (09 07 1808). Alemdar Pasha arrived Istanbul with his army and killed many rebels, he made Arif Efendi the Minister of Islamic issues and Arif Efendi went to Sultan Mustafa and said Sultan Selim III should ascend the throne again, Sultan Mustafa rejected Arif Efendi and commanded the death of Sultan Selim III and his brother Mahmud. Sultan Selim III was immideately killed but Mahmud had escaped. Alemdar Pasha dethroned Mustafa IV and Sultan Mahmud II replaced him.

Sultan Mustafa IV was executed in November 18 1808.

Mustafa was fond of calligraphy.