Author of the first major biography of Hazrat Muhammad, peace be upon him, which is based on carefully sifted hadith. Ibn Ishaq's Sirah was one of the most important sources on the life of Hazrat Muhammad, peace be upon him. Ibn Ishaq started to collect ahadith, which explained some of the passages of the Qura'an by relating them to the historical circumstances in which Hazrat Muhammad, peace be upon him, had received a particular revelation. Ibn Ishaq wrote a detailed sirah (biography) of the prophet, peace be upon him that stressed the virtue of the ansar and the iniquity of the Meccans who had opposed Hazrat Muhammad, peace be upon him. However, Ibn Hisham, who died 60 years after Ibn Ishaq, revised his book. A Gallium in English, Life of Muhammad, translated Ibn Hisham's book in 1955. Muhammad Ibn Ishaq was born in Madinah but studied in Alexandria and subsequently moved to Baghdad.