The honorific Muhiyudin denotes his status with many Sufis as a "reviver of religion". Gilani (Arabical-Jilani) refers to his place of birth, Gilan. However, Gilani also carried the epithet Baghdadi, referring to his residence and burial in Baghdad.
Gilani's father, Abu Saleh, was from a Sayyid lineage, tracing his descent from Hasan ibn Ali, a grandson of the Islamic prophet Muhammad. Abu Saleh was respected as a saint by the people of his day, and was known as Jangi Dost (meaning "fight-lover" in Persian), which was originally his father's sobriquet. Gilani's mother, Ummul Khair Fatima, was also a Sayyid, having been a descendant of Muhammad al-Jawad, himself descended from Husayn ibn Ali, the younger brother of Hasan.
Gilani spent his early life in Gilan, the province of his birth. In 1095, at the age of eighteen, he went to Baghdad. There, he pursued the study of Hanbali law under Abu Saeed Mubarak Makhzoomi and ibn Aqil. He studied Hadith with Abu Muhammad Ja'far al-Sarraj. His Sufi spiritual instructor was Abu'l-Khair Hammad ibn Muslim al-Dabbas. (A detailed description of his various teachers and subjects are included below). After completing his education, Gilani left Baghdad. He spent twenty-five years wandering in the deserts of Iraq.
School of law
Al-Jilani belonged to the Shafi'i and Hanbali schools of law. He placed Shafi'i jurisprudence (fiqh) on an equal footing with the Hanbali school (madhhab), and used to give fatwa according to both of them simultaneously. This is why al-Nawawi praised him in his book entitled Bustan al-'Arifin (Garden of the Spiritual Masters), saying: "We have never known anyone more dignified than Baghdad's Sheikh Muhyi al-Din 'Abd al-Qadir al-Jilani, may Allah be pleased with him, the Sheikh of Shafi'is and Hanbalis in Baghdad."
In 1127, Gilani returned to Baghdad and began to preach to the public. He joined the teaching staff of the school belonging to his own teacher, al-Mazkhzoomi, and was popular with students. In the morning he taught hadith and tafsir, and in the afternoon he held discourse on the science of the heart and the virtues of the Quran. He was said to have been a convincing preacher and converted numerous Jews and Christians. He was able to reconcile the mystical nature of Sufism with the sober demands of Islamic Law.
Sayings of Shaikh Abd al-Qadir al-Jīlānī Malfūzāt, Holland, Muhtar (translator). S. Abdul Majeed & Co, Kuala Lumpur (1994) ISBN1-882216-03-2.
Fifteen letters, khamsata ashara maktūban / Shaikh Abd Al-Qādir Al-Jīlānī. Translated from Persian to Arabic by Alī usāmu ́D-Dīn Al-Muttaqī. Translated from Arabic into English by Muhtar Holland.
Kamsata ašara maktūban. First ion. ʿAlāʾ al-Dīn, ʿAlī B., ʿAbd al-Malik al- Muttaqī al-Hindī (about 1480–1567) and Muhtar Holland (1935–). Al-Baz publications, Hollywood, Florida. (1997) ISBN1-882216-16-4.
Jalā Al-Khawātir: a collection of forty-five discourses of Shaikh Abd Al-Qādir Al-Jīlānī, the removal of cares. Chapter 23, pg 308. Jalā al-Khawātir, Holland, Muhtar (1935–) (translator). Al-Baz publications, Fort Lauderdale, Florida. (1997) ISBN1-882216-13-X.
The sultan of the saints: mystical life and teachings of Shaikh Syed Abdul Qadir Jilani / Muhammad Riaz Qadiri Qadiri, Muhammad Riyaz. Gujranwala, Abbasi publications. (2000) ISBN969-8510-16-8.
The sublime revelation: al-Fath ar-Rabbānī, a collection of sixty-two discourses / Abd al-Qādir al- Jīlānī, Second ion. al-Rabbānī, al-Fath. Al-Baz publications, Fort Lauderdale, Florida. (1998). ISBN1-882216-02-4.
Al-Ghunya li-talibi tariq al-haqq wa al-din, (Sufficient provision for seekers of the path of truth and religion), Parts one and two in Arabic. Al-Qadir, Abd, Al-Gaylani. Dar Al-Hurya, Baghdad, Iraq, (1988).
Al-Ghunya li-talibi tariq al-haqq wa al-din, (Sufficient provision for seekers of the path of truth and religion.) in Arabic. Introduced by Al-Kilani, Majid Irsan. Dar Al-Khair, Damascus, Bairut, (2005).
Geography of the Baz Ahhab second reading in the biography of Sheikh Abdul Qadir Jilani, and the birthplace of his birth according to the methodology of scientific research (MA in Islamic History from Baghdad University in 2001) of Iraqi researcher Jamal al-Din Faleh Kilani, review and submission of the historian Emad Abdulsalam Rauf،Publishe Dar Baz Publishing, United States of America, 2016, translated by Sayed Wahid Al-Qadri Aref.
^ abW. Braune, Abd al-Kadir al-Djilani, The Encyclopaedia of Islam, Vol. I, ed. H.A.R Gibb, J.H.Kramers, E. Levi-Provencal, J. Schacht, (Brill, 1986), 69;"authorities are unanimous in stating that he was a Persian from Nayf (Nif) in Djilan, south of the Caspian Sea."
^ abThe works of Shaykh Umar Eli of Somalia of al-Tariqat al-Qadiriyyah.
^Mihr-e-munīr: biography of Hadrat Syed Pīr Meher Alī Shāh pg 21, Muhammad Fādil Khān, Faid Ahmad. Sajjadah Nashinan of Golra Sharif, Islamabad (1998).
^Encyclopaedia of religion and ethics: volume 1. (A – Art). Part 1. (A – Algonquins) pg 10. Hastings, James and Selbie, John A. Adamant Media corporation. (2001), "and he was probably of Persian origin."
^The Sufi orders in Islam, 2nd ion, pg 32. Triingham, J. Spencer and Voll, John O. Oxford University Press US, (1998), "The Hanafi Qadirriya is also included since 'Abd al-Qadir, of Persian origin was contemporary of the other two."
^Devotional Islam and politics in British India: Ahmad Riza Khan Barelwi and his movement, 1870–1920, pg 144, Sanyal, Usha Oxford University Press US, 19 August 1999. ISBN0-19-564862-5ISBN978-0-19-564862-1.
^Cultural and religious heritage of India: Islam pg 321. Sharma, Suresh K. (2004)
^Indo-iranica pg 7. The Iran Society, Calcutta, India. (1985).
^Historical and political who's who of Afghanistan. p 177. Adamec, Ludwig W. (1975)
^Al-Ghunya li-talibi tariq al-haqq wa al-din (Sufficient provision for seekers of the path of truth and religion), parts one and two in Arabic, Al-Qadir, Abd and Al-Gilani. Dar Al-Hurya, Baghdad, Iraq, (1988).
^Al-Ghunya li-talibi tariq al-haqq wa al-din (Sufficient provision for seekers of the path of truth and religion) with introduction by Al-Kilani, Majid Irsan. Al-Kilani, Majid, al-Tariqat, 'Ursan, and al-Qadiriyah, Nash'at