Under Umar the country was divided into number of provinces. Historians differ about the exact number of provinces. Some say that the number of provinces was eight, while there are others who give a higher figure.
From the information that has come down to us, it appears that:
(1) Arabia was divided into two provinces, Mecca and Madina;
(2) Iraq was divided into two provinces, Basra and Kufa;
3) In the upper reaches of the Tigris and the Euphrates, Jazira was a province;
(4) Syria was a province;
(5) Umar divided Palestine in two provinces Aylya and Ramlah;
(6) Egypt was divided into two provinces, Upper Egypt and Lower Egypt;
(7) Persia was divided into three provinces, Khurasan; Azarbaijan and Fars.
Each province was in turn divided into districts. The exact number of districts is not known. In Persia alone the number of districts was 47. The total number of districts in the country must thus be around 100.
Each province was under the charge of a Governor or Wali. Other officers at the provincial level were:
(1) Katib, or Chief Secretary;
(2) Katib-ud-Diwan; Secretary, Army;
(3) Sahib-ul-Kharaj; Revenue Collector;
(4) Sahib-ul-Ahdath; Police Officer;
(5) Sahib-ul-Bait-ul-Mal, Treasury Officer
(6) Qadi, the Chief Judge.
In some districts there were separate military officers, though the Wali was in most cases the Commander-in-chief of the army quartered in the province.
During the Caliphate of Umar some of the notable Governors were:
(1) Abu Ubaidah was the Governor of Syria.
(2) Yazid b Abi Sufyan became the Governor of Syria after the death of Abu Ubaidah.
(3) Amir Mu'awiyah became the Governor of Syria after the death of his brother Yazid.
(4) Amr b. al-Aas was the Governor of Egypt.
(5) Saad b Abi Waqqas was the Governor of Kufah.
(6) Utbah b Ghazwan was the Governor of Basra.
(7) Abu Musa Ashari succeeded Utbah as the Governor of Basra.
(8) Itab b Usaid was the Governor of Mecca;
(9) Ayyad b Ghanam was the Governor of Jazira.
For every district, there were two main office holders, namely:
(l) Amil who was the main executive and responsible for the general administration; and
(2) Qadi responsible for the administration of justice.
Every appointment was made in writing. On appointment every officer was given an instrument of instructions in which his powers and duties were specified. On arrival at the headquarters of his charge, the officer in question was required to assemble the people and read the instrument of instructions before them. In this way the public became aware of the powers and obligations of the officers concerned, and could call them to account for any sins of omission or commission.
Umar's general instructions to his officers were: "Remember, I have not appointed you as commanders and tyrants over the people. I have sent you as leaders instead, so that the people may follow your example. Give the Muslims their rights and do not beat them lest they become abused. Do not praise them unduly, lest they fall into tht error of conceit. Do not keep your doors shut in their faces, lest the more powerful of them eat up the weaker ones. And do not behave as if you were superior to them, for that is tyranny over them."
At the time of appointment, every officer was required to make the promise:
(1) that he would not ride a Turkish horse;
(2) that he would not wear fine clothes;
(3) that he would not eat sifted flour;
(4) that he would not keep a porter at his door; and
(5) that he would always keep his door open to the public.
At the time of appointment a complete inventory of all the possessions of the person concerned was prepared and kept in record. If there was an unusual increase in the possessions of the office holder, he was immediately called to account, and the unlawful property was confiscated by the State.
The principal officers were required to come to Mecca on the occasion of the Hajj. In public assembly Umar invited all who had any grievance against any office to present the complaint. In the event of complaints inquiries were made immediately and grievances redressed on the spot.
Explaining the functions of the officers, Umar said: "Brethren, officers are appointed not that they should slap you in your faces and rob you of your properties, but in order that they should teach you the way of the Prophet of Allah. So, if any officer has acted contrary wise, tell me that I might avenge it."
A special office was established for the investigation of complaints that reached the Caliph every now and then against the officers of the State. The Department was under the charge of Muhammad b Maslamah Ansari a man of undisputed integrity. In important cases Muhammad b Maslamah was deputed by Umar to proceed to the spot, investigate the charge and take action. Sometimes an Inquiry Commission was constituted to investigate the charge. On occasions the officers against him complaints were received were summoned to Madina, and put to explanation by the Caliph himself.
In order to minimise the chances of corruption, Umar made it a point to pay high salaries to the staff. Provincial governor received as much as five thousand rupees a month besides their shares of the spoils of war.