But there was no indictment and no investigation.

But there was no indictment and no investigation. Khalid was summarily dismissed and he died in poverty and obscurity in 21 A.H. Umar's caliphate is notable for its many conquests. His generals conquered Iraq, Iran, Azerbaijan, Kirman, Seistan, Khurasan, Syria, Jordan, Palestine and Egypt, and incorporated them into the empire of the Muslims. All of these were permanent conquests. The Romans lost Syria, Palestine and Egypt for ever; and in Persia, the Sassani empire ceased to exist.

Among other events of the caliphate of Umar, were the first outbreak of plague in Syria in 18 A.H., and a famine in Hijaz in the same year. Between them, the plague and the famine killed more than 25,000 people (Suyuti and Abul Fida). Civil and Military Administration and Policy Since the empire had grown enormously in all directions, Umar had to establish an administrative system. But the Arabs did not have any experience in administration.

Umar, therefore, left the Persian and the Roman framework of administration in the conquered provinces undisturbed. The Persian and the Roman staff carried on the day-to-day work as before. Umar founded numerous military cantonments in Iraq, Syria and Egypt. Since he wanted the Arabs to be a purely fighting and ruling class, he did not allow them to buy land and to settle down or to become farmers in the conquered territories.

To assess land revenue, Umar again had to retain the Persian and the Romans systems. But in Iraq it was found necessary to survey the arable lands and to assess tax on them. Arabs knew less than nothing about assessing land revenue. There was, however, one exception in Uthman bin Hunaif of Medina. He was a man of outstanding ability as a revenue expert.

Though it was Umar's policy not to appoint the citizens of Medina (Ansar) to any important positions, in this particular case he had no choice, and he appointed Uthman bin Hunaif as the commissioner of land development in Iraq. Qadi Yusuf says that Uthman bin Hunaif was an authority in all Arabia on taxation, assessment of land revenue and land reclamation (Kitabul-Kharaj and Siyar-ul-Ansar).

Within less than a year, Uthman bin Hunaif had completed the job of taking measurements of the whole new province, and of making assessments for the collection of land revenue. He was, thus, the first Financial Commissioner of Iraq, and incidentally, one of the few Ansaris to hold any position of authority in the caliphates of Abu Bakr, Umar and Uthman bin Affan.