
From the life of Hazrat Umar (ra) bin Khattab
During the era of Hazrat Umar (ra), countries were divided into provinces. In 20AH, Hazrat Umar (ra) split the occupied territories into eight provinces so that administrative affairs could be better dealt with:
(Al-Farooq, Shibli Naumani, p. 185, Dar-ul-Ishaaat Karachi [1991])