This book was published in tribute to Khalid Bin Al-Waleed, whom is believed to be "the greatest military general in history", and who campaigned in the Middle East about 630-650 C.E. The biography of Khalid came from Hafiz Ibn Kathir and Mohammad bin Ishaq. It was later revised by A.I. Akram. Lt. General A. I. Akram was a Pakistani army officer who taught at the Pakistani Staff College in 1964, and who later traveled to Saudi Arabia and the Middle East. Khalid Bin Al-Waleed was a commander in the service of prophet Muhammad (peace be upon him) and the caliphs Abu Bakr (r. 632-634) and Umar (r. 634-644) who played a leading role in the Ridda wars against rebel tribes in Arabia in 632-633 and the conquests of Sasanian Iraq in 633-634 and Byzantine Syria in 634-638. Khalid was a horseman of the Quraysh tribe's aristocratic Makhzum clan, which ardently opposed the Prophet (peace be upon him). Later he was made a commander by the Prophet, who bestowed on him the title Sayf Allah (the Sword of God).