He was the Imaam, the Shaykh, Muhammad ibn 'Abdul-Wahhaab ibn Sulaymaan ibn 'Alee ibn Muhammad ibn Ahmad ibn Raashid ibn Burayd ibn Muhammad ibn Mushrif ibn 'Umar, from a branch of the tribe of Banoo Tameem.
This scholar was born in the town of 'Unayzah in the year 1115 H in a household known for knowledge, nobility and attachment to the religion. His father was an eminent scholar, and his grandfather was the scholar of Najd in his time. He himself memorized the Qur'aan before reaching the age of ten, and studied fiqh (details of Islamic law and practice) of which he learned a great deal. Indeed his father was greatly pleased at the strength of his memory. He devoted a great deal of time to studying the books of tafseer (explanation of the Qur'aan) and hadeeth (the sayings and actions of the Prophet). He sought knowledge day and night and he used to memorise the books of the various branches of Islamic knowledge. He also travelled throughout Najd and to Makkah and studied the books of knowledge with the scholars. Then he travelled to al-Madeenah and studied under the scholars there. From them was the great scholar Shaykh 'Abdullah ibn Ibraaheem ash-Shammaree. He also studied under his son who was well versed in the laws of inheritance, Ibraaheem ash-Shammaree, the author of al-'Adhbul-Faa'id fee Sharh Alfiyyatil Faraa'id. It was they who introduced him to the famous scholar of hadeeth Muhammad Hayaat as-Sindee. With him he studied the sciences of hadeeth and sciences related to its narrators. He also granted him permission (ijaazah) to narrate the source books of hadeeth.
Shaykh Muhammad ibn 'Abdul-Wahhaab (may Allaah, the Most High, have mercy upon him) was granted deep understanding and a very high degree of intelligence by Allaah, and he devoted his time to research, study and writing. He used to record and remember whatever points of benefit he came across whilst reading and researching and he never grew tired of writing. Indeed he transcribed many of the works of Ibn Taymiyyah and Ibnul-Qayyim (rahimahumullaah) and many valuable manuscripts written in his own handwriting are preserved in various museums. After the death of his father he himself openly called to the Salafee da'wah, to singling out Allaah with all worship and all that is His due, to the rejection of all evil, and he opposed the innovators who directed worship to the graves. He was aided, strengthened and his call to the truth was made widespread through the help of the Aal Sa'ood.
He also published many beneficial works, from them: The outstanding and valuable work entitled: Kitaabut-tawheed, which has been printed many times; every time an edition is sold out it is reprinted. Also Kashfush-Shubuhaat, al-Kabaa’ir, Mukhtasarul-Insaaf, ash-SharhuUKabeer, Mukhtasar Zaadil-Ma'aad, and he has a large number of Fataawaa (religious rulings) and treatises, which have been collected under the title: Majmoo 'ah Muallafaat al-Imaam Muhammad ibn 'Abdul-Wahhaab, under the supervision of Imaam Muhammad ibn Sa'ud University.
He died in the year 1206 H. May Allaah cover him in mercy and reward him well for his services to Islaam and the Muslims. Indeed Allaah is the One who hears and responds to supplications. All praise and thanks are for Allaah - and may Allaah send praises and blessings of peace upon our Prophet Muhammad, upon his family, true followers, and upon all his Companions.
By Fahd ibn Naasir as-Sulaymaan, from the book 'Expalanation of the Three Fundamental Principles of Islam'.