Imam Ahmad bin Ali bin Hajr is one of the greatest authorities in the sciences of Hadith. He is best known for his commentary on Sahih al-Bukhari, Fath al-Bari.

However, he has significant works in all sciences of Hadith. His accuracy (Tahqeeq) in the works he produced stands out and is the main reason for heavy reliance upon his books.

Imam Ibn Hajr passed away in the year 852 Hijri.