Abū Luʾluʾ (d. 23/644), was the murderer of ʿUmar b. al-Khaṭṭāb, the second of the ‘rightly-guided’ caliphs. Virtually nothing is known about his life. His reputation rests solely on his killing of ʿUmar. Most sources give his name as Fīrūz (Ḥassān b. Thābit, 1/273; Ibn Ḥabīb, ‘Asmāʾ’, 155; Ibn Qutayba, 183). There is little agreement among the sources on the subject of his ancestry and beliefs, and later sources yield little useful information beyond repeating the findings of earlier accounts. A…