Toulon, one of the twenty-four tribes that inhabited Turkestan, had his family residing near Lake Lob in Bukhara the Lesser. He was captured in a battle and brought to Ibn Assad al-Dimashqi, one of al-Ma'mun's officials, who paid an annual tribute of Mamluks, Turkish horses, and other items. In the year 200 AH, Toulon was among a group of Mamluks sent by Ibn Assad. He was well-proportioned and strong. Al-Ma'mun was pleased with him and attached him to his retinue, eventually making him the head of his guard and bestowing upon him the title of "Amir al-Sitr" (Prince of the Veil). This position was only granted to those in whom the Caliph had special trust in their honesty and loyalty, to guard his personal secrets. After serving in this position for about 10 years during the reigns of al-Ma'mun and al-Mu'tasim, Toulon became a prominent figure with a family, including a son named Ahmad, who was later known as Abu al-Abbas and was the founder of the Tulunid dynasty. He was born in Baghdad. Others said he was born in Samarra in the year 200 AH to a Turkish slave woman named Qasima, whom some called Hashima, and who was among the concubines. Still others said he was the son of Mawbi, a servant of Toulon, and that Toulon raised him from a young age. The most accurate account is that he was the son of Toulon.

Before anyone recognized Toulon's significance, al-Mu'tasim died, and his son Harun Abu Ja'far was appointed as his successor, taking the title al-Wathiq billah. In the first year of his caliphate, he dismissed most of the governors and officials appointed by his father. He intended to dismiss Ishak ibn Ibrahim from the governorship of Egypt, but he did not do so until Ishak died in 230 AH. He was replaced by Ali ibn Yahya al-Armani in Fustat. A few years later, in 234 AH, he was replaced by Muhammad ibn al-Fadl ibn Musa. The Caliph al-Wathiq billah died in 232 AH, during the caliphate of al-Mutawakkil ibn al-Mu'tasim. He was 27 years old and ruled for 5 years and 10 months.

Upon the Caliph's death, his two viziers, Ahmad ibn Abi Dawud and Muhammad ibn Abd al-Malik, known as al-Zayyat, conspired with the Turkish chief of the guard to pledge allegiance to Muhammad ibn al-Wathiq, who was given the title Ja'far ibn al-Mu'tasim billah. They saw that his age was not suitable for issuing judgments, so they deposed him. They then pledged allegiance to al-Mutawakkil billah and gave him the title al-Mutawakkil ala Allah. Al-Wathiq and al-Mutawakkil were full brothers, meaning they shared the same father and mothers. The mother of the first was a Byzantine slave named Qratis, and the mother of the second was a Turkish slave named Sarja.