Shihab al-Din Abu al-Fadl Ahmad ibn Ali ibn Hajar al-Asqalani (773-852 AH / 1372-1449 CE) was one of the greatest hadith scholars in Islamic history. Born in Cairo, he served as the chief Shafi'i judge of Egypt. His monumental work Fath al-Bari is considered the most authoritative commentary on Sahih al-Bukhari. He also authored Tahdhib al-Tahdhib, Bulugh al-Maram, and al-Isabah fi Tamyiz al-Sahabah (a biographical dictionary of the Companions). His scholarship earned him the title Amir al-Mu'minin fil-Hadith (Commander of the Faithful in Hadith).