Umar II

According to the traditional Muslim sources, when Sulayman was on his deathbed in Dabiq, he was persuaded by Raja to designate Umar as his successor.[2][10][11][12] Sulayman's son Ayyub had been his initial nominee, but predeceased him,[13] while his other sons were either too young or away fighting on the Byzantine front.[11] The nomination of Umar voided the wishes of Abd al-Malik, who sought to restrict the office to his direct descendants.[2] The elevation of Umar, a member of a cadet branch of the dynasty, in preference to the numerous descendants of Abd al-Malik surprised these princes.[12] According to Wellhausen, "nobody dreamed of this, himself [Umar] least of all".[12] Raja managed the affair, calling the Umayyad princes into Dabiq's mosque and demanding that they recognize Sulayman's will, which Raja had kept secret.[12] Only after the Umayyads accepted did Raja reveal that Umar was the caliph's nominee.[12] Hisham ibn Abd al-Malik voiced his opposition, but relented after being threatened with violence.[12] A potential intra-dynastic conflict was averted with the designation of a son of Abd al-Malik, Yazid II, as Umar's successor.[11]

According to the historian Reinhard Eisener, Raja's role in the affair was likely "exaggerated"; "more reasonable" was that Umar's succession was the result of "traditional patterns, like seniority and well-founded claims" stemming from Caliph Marwan I's original designation of Umar's father, Abd al-Aziz, as Abd al-Malik's successor,[14] which had not materialized due to Abd al-Aziz predeceasing Abd al-Malik.[15] Umar acceded without significant opposition on 22 September 717.[2]

Silver dirham of Umar ibn Abd al-Aziz

The most significant reform of Umar II was effecting the equality of Arabs and mawali (non-Arab Muslims). This was mainly relevant to the non-Arab troops in the Muslim army, who had not been entitled to the same shares in spoils, lands and salaries given to Arab soldiers. The policy also applied to Muslim society at large.[16] Under previous Umayyad rulers, Arab Muslims had certain financial privileges over non-Arab Muslims. Non-Arab converts to Islam were still expected to pay the jizya (poll tax) that they paid before becoming Muslims. Umar put into practice a new system that exempted all Muslims, regardless of their heritage, from the jizya tax. He also added some safeguards to the system to make sure that mass conversion to Islam would not cause the collapse of the finances of the Umayyad government.[17] Under the new tax policy, converted mawali would not pay the jizya (or any other dhimmi tax), but upon conversion, their land would become the property of their villages and would thus remain liable to the full rate of the kharaj (land tax). This compensated for the loss of income due to the diminished jizya tax base.[18] He issued an edict on taxation stating:

Whosoever accepts Islam, whether Christian, Jew or Zoroastrian, of those now subject to taxes and who joins himself to the body of the Muslims in their abode, forsaking the abode in which he was before, he shall have the same rights and duties as they have, and they are obliged to associate with him and to treat him as one of themselves.[19]

Possibly to stave off potential blowback from opponents of the equalization measures, Umar expanded the Islamization drive that had been steadily strengthening under his Marwanid predecessors. The drive included measures to distinguish Muslims from non-Muslims and the inauguration of an Islamic iconoclasm.[20] He put a stop to the ritual cursing of Caliph Ali (r. 656–661), the cousin and son-in-law of Muhammad, in Friday prayer sermons.[20] The ritual had begun under Ali's opponent and future founder of the Umayyad Caliphate Mu'awiya I during the First Muslim Civil War.

Umar II is credited with having ordered the first official collection of hadith (sayings and actions attributed to the Islamic prophet Muhammad), fearing that some of it might be lost. Abu Bakr ibn Muhammad ibn Amr ibn Hazm and Ibn Shihab al-Zuhri are among those who compiled hadiths at Umar II's behest.[21]

Shortly after his accession, Umar overhauled the administrations of the provinces.[2] He appointed competent men that he could control, indicating his intention "to keep a close eye on provincial administration".[10] Wellhausen noted that the caliph did not leave the governors to their own devices in return for their forwarding of the provincial revenues; rather, he actively oversaw his governors' administrations and his main interest was "not so much the increase of power as the establishment of right".[22]

He subdivided the vast governorship established over Iraq and the eastern Caliphate under Abd al-Malik's viceroy al-Hajjaj ibn Yusuf.[10] Sulayman's appointee to this super-province, Yazid ibn al-Muhallab, was dismissed and imprisoned by Umar for failing to forward the spoils from his earlier conquest of Tabaristan along the southern Caspian coast to the caliphal treasury.[10][23] In place of Ibn al-Muhallab, he appointed Abd al-Hamid ibn Abd al-Rahman ibn Zayd ibn al-Khattab, a member of Caliph Umar I's family, to Kufa, Adi ibn Artah al-Fazari to Basra, al-Jarrah ibn Abdallah al-Hakami to Khurasan and Amr ibn Muslim al-Bahili, a brother of the conqueror Qutayba ibn Muslim, to Sind. He appointed Umar ibn Hubayra al-Fazari to the Jazira (Upper Mesopotamia). Although many of these appointees were pupils of al-Hajjaj or affiliated with the Qays faction, Umar chose them based on their reliability and integrity, rather than opposition to Sulayman's government.[23]

Umar appointed al-Samh ibn Malik al-Khawlani to al-Andalus (Iberian Peninsula) and Isma'il ibn Abd Allah to Ifriqiya. He chose these governors because of their perceived neutrality in the tribal factionalism between the Qays and Yaman and justice toward the oppressed.[24]

The Second Arab Siege of Constantinople, as depicted in the 14th-century Bulgarian translation of the Manasses Chronicle.

After his accession in late 717, Umar ordered the withdrawal of the Muslim army led by his cousin Maslama ibn Abd al-Malik from their abortive siege against Constantinople to the regions of Antioch and Malatya, closer to the Syrian frontier.[2] He commissioned an expedition in the summer of 718 to facilitate their withdrawal.[25] Umar kept up the annual summer raids against the Byzantine frontier,[2] out of the obligation to jihad.[8] He remained in northern Syria, often residing at his estate in Khunasira, where he built a fortified headquarters.[2][26]

At some point in 717, he dispatched a force under Ibn Hatim ibn al-Nu'man al-Bahili to Adharbayjan to disperse a group of Turks who had launched damaging raids against the province.[2] In 718, he successively deployed Iraqi and Syrian troops to suppress the Kharijite rebellion of Shawdhab al-Yashkuri in Iraq, though some sources say the revolt was settled diplomatically.[2]

Umar is often deemed a pacifist by the sources and Cobb attributes the caliph's war-weariness to concerns over the diminishing funds of the caliphal treasury.[2] Wellhausen asserts that Umar was "disinclined to wars of conquest, well-knowing that they were waged, not for God, but for the sake of spoil".[8] Blankinship considers this reasoning to be "insufficient".[27] He proposed it was the massive losses faced by the Arabs in their abortive siege against Constantinople, including the destruction of their navy, that caused Umar to view his positions in al-Andalus, separated by the rest of the Caliphate by sea, and Cilicia as acutely vulnerable to Byzantine attack. Thus he favored withdrawing Muslim forces from these two regions. This same calculus led to him to consider withdrawing Muslim forces from Transoxiana so as to shore up the defenses of Syria.[28] Shaban views Umar's efforts to curb offensives as linked to the resentment of the Yamani elements of the army, who Shaban views to have been politically dominant under Umar, at excessive deployments in the field.[27]

Although he halted further eastward expansion, the establishment of Islam in a number of cities in Transoxiana, precluded Umar's withdrawal of Arab troops from there.[29][23] During his reign, the Muslim forces in al-Andalus conquered and fortified the Mediterranean coastal city of Narbonne in modern-day France.[30]

Following the example of the Prophet, Umar sent out emissaries to China and Tibet, inviting their rulers to accept Islam. According to Nazeer Ahmed, it was during the time of Umar ibn Abd al-Aziz that Islam took roots and was accepted by a large segment of the population of Persia and Egypt. When the officials complained that because of conversions, the jizya revenues of the state had experienced a steep decline, Umar wrote back saying that he had accepted the Caliphate to invite people to Islam and not to become a tax collector. The infusion of non-Arabs in large number into the fold of Islam shifted the center of gravity of the empire from Medina and Damascus to Persia and Egypt.[31]

Shah Waliullah Dehlawi, an 18th century Sunni Islamic scholar, stated:[37]

A Mujadid appears at the end of every century: The Mujadid of the 1st century was Imam of Ahlul Sunnah, Umar ibn Abd al-Aziz. The Mujadid of the 2nd century was Imam of Ahlul Sunnah Muhammad Idrees Shaafi. The Mujadid of the 3rd century was Imam of Ahlul Sunnah Abu Hasan Ashari. The Mujadid of the 4th century was Abu Abdullah Hakim Nishapuri.

The third Islamic century famous scholar and poet Al-Taymi said:

There were three great caliphs: Abu Bakr, who fought the Apostates until they surrendered; Umar ibn Abd al-Aziz, who made good the abuse of Umayyads and Al-Mutawakkil, who abolished heretical innovations and publicly proclaimed Sunnah[38]

In his al-Futūḥāt al-Makkiyya, Ibn Arabi claimed that Mu'awiya II was a spiritual Pole (Ghawth) of his time and one of the few in history having such a spiritual degree combined with a temporal power, like the Rashidun caliphs and caliph Umar ibn Abd al-Aziz.[39]