In the sīra literature, the most important extant biography are the two recensions of Ibn Ishaq's (d. 768), now known as "Sīrat Rasūl Allah" ("Biography/Life of the Messenger/Apostle of Allah"), which survive in the works of his editors, most notably Ibn Hisham (d. 834) and Yunus b. Bukayr (d.814–815), although not in its original form. According to Ibn Hisham, Ibn Ishaq wrote his biography some 120 to 130 years after Muhammad's death. Many, but not all, scholars accept the accuracy of these biographies, though their accuracy is unascertainable.