Abu `Abdullah Muhammad Ibn ‘Omar Ibn Waqid al-Aslami (Arabic أبو عبد الله محمد بن عمر بن واقد الاسلمي) (c. 130 – 207 AH; c. 747 – 823 AD) was a historian commonly referred to as al-Waqidi (Arabic: الواقدي). His surname is derived from his grandfather's name Waqid and thus he became famous as al-Imam al-Waqidi. Al-Waqidi was an early Muslim historian and biographer of the Islamic prophet Muhammad, specializing in his military campaigns. He served as a judge (qadi) for the Abbasid caliph al-Ma'mun. Several of al-Waqidi's works are known through his scribe and student (in the field of the al-maghazi genre), Ibn Sa'd.