Abu Hamid Muhammad ibn Muhammad al-Ghazali, known as Algazel to the western medieval world, was born and died in Tus, in the Khorasan province of Persia (modern day Iran). He was a Muslim theologian, jurist, philosopher, physician, psychologist and mystic, and remains one of the most celebrated scholars in the history of Sufi Islamic thought. He is considered a pioneer of the methods of doubt and skepticism, and in one of his major works, The Incoherence of the Philosophers, he changed the course of early Islamic philosophy, shifting it away from the influence of ancient Greek and Hellenistic philosophy, and towards cause-and-effect that were determined by God or intermediate angels.

Ghazali's father, a traditional sufi, died when he and his younger brother, Ahmad Ghazali, were still young. One of their father's friends took care of them for the next few years. In 1070, Ghazali and his brother went to Gurgan to enroll in a madrassah. There, he studied fiqh (islamic jurisprudence). After approximately 7 years studying, he returned to Tus.

His first important trip to Nishapur occurred around 1080 when he was almost 23 years old. He became the student of the famous muslim scholar known as Imam al-Haramayn. After the death of Al-Juwayni in 1085, Ghazali was invited to go to the court of Nizamul Mulk Tusi, the powerful vizier of the Seljuq sultans. The vizier was so impressed by Ghazali's scholarship that in 1091 he appointed him as chief professor in the Nizamiyya of Baghdad. He used to lecture to more than 300 students, and his participation in Islamic debates and discussions made him popular in all over the Islamic territories.

He passed through a spiritual crisis in 1095, abandoned his career, and left Baghdad on the pretext of going on pilgrimage to Mecca. Making arrangements for his family, he disposed of his wealth and adopted the life of a poor Sufi. After some time in Damascus and Jerusalem, with a visit to Medina and Mecca in 1096, he settled in Tus to spend the next several years in seclusion. He ended his seclusion for a short lecturing period at the Nizamiyyah of Nishapur in 1106. Later he returned to Tus where he remained until his death in December, 1111. He had one son named Abdu'l Rahman Allam.