From that time onwards, the star of Ahmad ibn Tulun began to rise in the political arena. His father died in the year 242 AH, when he was seventeen years old. This was during the reign of Al-Mutawakkil, who saw in Ahmad the suitability to succeed his father in the Emirate of Egypt. Ahmad had been well-educated and raised, pious, of good character, gentle, brave, and skilled in politics. He was fond of studying hadith and was known for his piety. He gained the favor of all the Turkish officers in the Caliph's court, including one of their leaders, Barquq, who married his daughter to Ahmad, and they had a son named Abbas.

This was followed by the deposition of Al-Musta'in. The Turkish Mamluks, who served in the Caliphs' courts and were recruited, as previously mentioned, were increasing in number and strength since the days of Al-Mu'tazz. They rose to high positions, and the reins of the state fell into their hands, which they managed as they pleased. Before the death of Al-Mutawakkil, they were content with deposing and appointing princes and viziers, and killing those who were not to their liking. However, after that, they were no longer satisfied with anything less than interfering in the deposition and appointment of the Caliphs. If they did not like a Caliph, they would seek to replace him, rallying their factions and carrying out their plans. The appointment of Al-Musta'in was due to the efforts of some of the leaders of the personal guard, which displeased some others, who then began to seek his deposition. They deposed him in the year 252 AH, after he had ruled for three years and a few months.

Al-Mu'tazz, son of Al-Mutawakkil, succeeded him. After the deposition of Al-Musta'in, they pledged allegiance to Al-Mu'tazz, who was the son of Al-Mutawakkil and brother of Al-Muntasir. He had been deprived of his right to the Caliphate since his father was killed, and he was imprisoned at that time. After he escaped from prison in Samarra with his brother Al-Mu'ayyad billah, their cousin Al-Musta'in returned them to confinement. The factions that gained power afterwards and deposed Al-Musta'in had no involvement in this. They came to Samarra on the 7th of Muharram in the year 252 AH. After Al-Mutawakkil was killed, they released Al-Mu'tazz from his chains and pledged allegiance to him on the day of Thursday. They forced Al-Musta'in to abdicate, which he did. They then moved him to a fortress and placed guards over him. Afterwards, they sent him to Wasit in a convoy led by Ahmad ibn Tulun, and he was killed on the way. It is said that the chamberlain Sa'id was the one who killed him on the orders of Al-Mu'tazz billah. Others said that Ahmad ibn Tulun himself did it with his own hand. However, the majority agreed to absolve him of this terrible accusation.

In the year 252 AH, a group of rebels revolted.