Taqiyyu d'Ddin Ahmad ibnu Taymiyyah , known as Ibn Taymiyyah, was a Sunni Muslim theologian, jurisconsult, and reformer.

He was born in 661 AH, 1263 CE at Harran, Turkey, and died in 728 AH, 1328 CE at Damascus, Syria. He was never married, so his life was dedicated to learning, writing, and teaching.

He was folowing the Hanbali school of jurisprudence founded by Ahmad ibnu Hanbal. He was also a member of the Qadiriyya Sufi order founded by Abdul-Qadir Gilani.

Even if he was of sunnite doctrine, Ibn Taymiyyah had some nonconforming views regarding the Hanbali jurisprudence, and all the three oher Mathaahib (doctrines). This what he made him reformer (Mujaddid) .

Beside his rejection of some traditions, the main view is that the veneration of saints and the visitation to their tomb-shrines is not acceptable.

Ibn Taymiyah believed that Islam was perfect and complete at the days of the companion (the time of As-Salaf As-Salih), so he was against Sufism , Shi'a, Christians, Mutazila, and philosophers.

This opinions made him unpopular with the majority of the religious scholars of the time, under whose orders he was imprisoned several times, in Damascus, Cairo and Alexandria.

His particular interpretations of the Qur'an and the Sunnah and his teachings had made him one of the most influential writers in contemporary Islam.

Sunni scholars of the Ibnu Taymiyyah denounced him. In their fatwa, they called Ibn Taymiyah as a misguided person who was deserting the Sunni tenets. Some of them went so far as to declare his writings as Kufr.

In addition to Al-Qa'ida and other jihadi groups, Ibn Taymiyyah has paticularly and profoundly influenced Muhammad ibnu Abdul-Wahhab, the founder of Wahhabism, and Hassan Albanna, the founder of Muslim Brotherhood in Egypt, at the beginning of the 20th century.

Ibn Taymiyya was given the title of "Sheikh ul-Islam" by his supporters but his adversaries contested this use. This honorific position allows issuing "Fataws" (plural of fatwa).

A fatwa is an authoritative verdict that the Sheikh'ul- Islam, a qualified jurist or "mufti", can give on issues pertaining to the Islamic law. The person who issues a fatwa is called, in that respect, a mufti, i.e. an issuer of fatwa.

The students of Ibn Taymiyyah were Ibnu Kathiir, Ibnu Qayyim Jawzi and Adh-Dhahabi.

Ibn Taymiyyah's total works have not all survived and his extant works of thirty five volumes are incomplete. Extant books and essays written by ibn Taymiyyah include:

• A Great Compilation of Fatwa, collected centuries after his death,
• Minhaj as-Sunnah an-Nabawiyyah ,
• Al-Aqidah al-Waasitiyyah,
• Fatawa al-Kubra,
• Fatawa al-Misriyyah .
• The religious and moral doctrine of Jihad
• The status of Jihad in Islam

Ibnu Taymiyyah had manifested his knowledge with action. He , himself, was engaged in the Jihad against the Tatars in a country dominated then by the Mamluks.
Jihad means the great effort on the path of God.

These invaders took rule and judged by "al-Yasiq", which is a book forged by Genghis Khan, the founder and first Great Khan of the Mongol Empire.

al-Yasiq corresponds to a book of laws composed of different Jewish, Christian and Muslim legislation, and where Genghis Khan put many laws that he simply drew from his thoughts and passions. It was put forward in judgments by the Qur'an and the Sunnah.

Sheikh-Al Islam Ibnu Taymiyyah declared Kufr upon them for this act of apostasy, and waged Jihad against them for consecutive years by forming many battalions, until the ruling state returned to the Al-Muwahidoon.

So Ibnu Taymiyyah forged his theory of Jihad from some specif verses of Quar'an and some specif hadiths.

For istance, in his book "Majmu'at Al-Fatawi", part 28, page 394, Chapter Al-Jihad, He said:

“Whomsoever the Da'wah (invitation) of the Messenger sallallahu alayhi wa salam has reached them to the Deen (religion) of Allah, with which he was sent , and they do not respond to it, it then becomes an obligation to fight them

According to the the verse “..until there is no more Fitnah (oppression(, and the Deen is for Allah alone.” [Suratat Al-Anfaal: 39]

There is also a hadiith that use the Jihadists. It is written in the two Saheeh collections Al-Bukhari #2946 and Muslim #21. This hadith says:

“I have been commanded to fight the people up until they bear witness that there is no deity worthy of worship except Allah alone. Whoever declares that, then their blood and their wealth are safeguarded from me, except that which [Allah] has a right upon, and their account is with Allah.”

All the verses of Qur'an and the Hadiths of this kind need to be used by Ahl Al-Uqul (those who has a spirit) to use them , if they are authentic, exactly in their contexts and exactly where they should be, and to extract the appropriate interpretation.

The infuence of Ibnu Taymiyya is manifested in organizations like Wahhabism, Salafism, Qutbism (Muslim Brotherhood), Jihadism, Al-Qa'ida, An-Nusra (Islamic Front), and ISIS (Daa'ish).

We are seeing , nowadays, Islamists Shuyukhs manipulate and distort the Ibnu Taymiyya’s work and find the way, by issuing a fatwa, to manipulate victims, and, by the name of the Qur'an and the Sunnah , the legitimise their actions aftermath.

To recap, the work of Ibnu Taymiyya has to be reviewed and corrected, if it's worth it.