By the Arab writer, historian ad poet, Muhammad ibn 'Abd al-Jabbar 'Utbi (d.427/1036). A history of Sultan Mahmud of Ghazni, (971–1030 CE) the important ruler of the Ghaznavid Empire, includes biographical information and the history on wars and political relations. During his reign, Mahmud extended the Ghaznavid Empire into what is today most of Afghanistan, eastern Iran, Pakistan and northwestern India, with the city of Ghazna as the capital.