Ibn Ishaq
Muḥammad ibn Isḥāq ibn Yasār ibn Khiyār (according to some sources, ibn Khabbār, or Kūmān, or Kūtān, Arabic: محمد بن إسحاق بن يسار بن خيار, or simply ibn Isḥaq ابن إسحاق, meaning "the son of Isaac") (died 767, or 761) was an Arab Muslim historian and hagiographer. Under the aegis of the 'Abbasid caliph Al-Mansur, Ibn Ishaq collected oral traditions that formed the basis of the most important biography of the Islamic prophet Muhammad.
Read more about Ibn Ishaq: Life, Biography of Muhammad, Other Works, Reliability of His Ahadith