He allied with the province's powerful Banu Kalb tribe, developed the defenses of its coastal cities, and directed the war effort against the Byzantine Empire, including the first Muslim naval campaigns.

[17] Upon the accession of Caliph Uthman (r. 644–656), Mu'awiya's governorship was enlarged to include Palestine, while a companion of Muhammad, Umayr ibn Sa'd al-Ansari, was confirmed as governor of the Homs-Jazira district.

[22] During the reign of Uthman, Mu'awiya allied with the Banu Kalb,[23] the predominant tribe in the Syrian steppe extending from the oasis of Dumat al-Jandal in the south to the approaches of Palmyra and the chief component of the Quda'a confederation present throughout Syria.

[38][39] To help pay for his troops, Mu'awiya requested and was granted ownership by Uthman of the abundant, income-producing, Byzantine crown lands in Syria, which were previously designated by Umar as communal property for the Muslim army.

[37][44] Umar had rejected Mu'awiya's request to launch a naval invasion of Cyprus, citing concerns about the Muslim forces' safety at sea, but Uthman allowed him to commence the campaign in 647, after refusing an earlier entreaty.

[69] Although he had the firm backing of the Kalb, to shore up the rest of his base in Syria, Mu'awiya was advised by his kinsman al-Walid ibn Uqba to secure an alliance with the Yemenite tribes of Himyar, Kinda and Hamdan, who collectively dominated the Homs garrison.

[72] When Ali sent his envoy, the veteran commander and chieftain of the Bajila, Jarir ibn Abd Allah, to Mu'awiya, the latter responded with a letter that amounted to a declaration of war against the caliph, whose legitimacy he refused to recognize.

[74] During the truce, Mu'awiya dispatched an embassy led by Habib ibn Maslama, who presented Ali with an ultimatum to hand over Uthman's alleged killers, abdicate and allow a shura (consultative council) to decide the caliphate.

[79][g] According to the account of the scholar al-Zuhri (d. 742), this prompted Amr ibn al-As to counsel Mu'awiya the following morning to have a number of his men tie leaves of the Qur'an on their lances in an appeal to the Iraqis to settle the conflict through consultation.

[79][88] Information in the early Muslim sources about the time, place and outcome of the arbitration is contradictory, but there were likely two meetings between Mu'awiya's and Ali's respective representatives, Amr and Abu Musa al-Ash'ari, the first in Dumat al-Jandal and the last in Adhruh.

[94] In July, Mu'awiya dispatched an army under Amr to Egypt after a request for intervention from pro-Uthman mutineers in the province who were being suppressed by the governor, Caliph Abu Bakr's son and Ali's stepson, Muhammad.

[102] In Yemen, Busr executed several notables in Najran and its vicinity on account of past criticism of Uthman or ties to Ali, massacred numerous tribesmen of the Hamdan and townspeople from Sana'a and Ma'rib.

[110] The 10th-century Jerusalemite geographer al-Maqdisi holds that Mu'awiya had further developed a mosque originally built by Caliph Umar on the Temple Mount, the precursor of the Jami Al-Aqsa, and received his formal oaths of allegiance there.

[117] The highest stipends were paid on an inheritable basis to 2,000 nobles of the Quda'a and Kinda tribes, the core components of his support base, who were further awarded the privilege of consultation for all major decisions and the rights to veto or propose measures.

[30] In the Jazira, Mu'awiya coped with the tribal influx, which spanned previously established groups such as the Sulaym, newcomers from the Mudar and Rabi'a confederations and civil war refugees from Kufa and Basra, by administratively detaching the military district of Qinnasrin–Jazira from Homs, according to the 8th-century historian Sayf ibn Umar.

[137] Challenges to central authority in general, and to Mu'awiya's rule in particular, were most acute in Iraq, where divisions were rife between the ashraf upstarts and the nascent Muslim elite, the latter of which was further divided between Ali's partisans and the Kharijites.

Mu'awiya's initial choice to govern Kufa in 661 was al-Mughira ibn Shu'ba, who possessed considerable administrative and military experience in Iraq and was highly familiar with the region's inhabitants and issues.

[143] In a controversial step that secured the loyalty of the fatherless Ziyad, whom the caliph viewed as the most capable candidate to govern Basra,[141] Mu'awiya adopted him as his paternal half-brother, to the protests of his own son Yazid, Ibn Amir and his Umayyad kinsmen in the Hejaz.

[141] Ziyad tackled Iraq's core economic problem of overpopulation in the garrison cities and the consequent scarcity of resources by reducing the number of troops on the payrolls and dispatching 50,000 Iraqi soldiers and their families to settle Khurasan.

[95][124] Maslama remained governor for the duration of Mu'awiya's reign,[124] significantly expanding Fustat and its mosque and boosting the city's importance in 674 by relocating Egypt's main shipyard to the nearby Roda Island from Alexandria due to the latter's vulnerability to Byzantine naval raids.

According to the Muslim literary tradition, in the plain of Arafat and the barren valley of Mecca he dug numerous wells and canals, constructed dams and dikes to protect the soil from seasonal floods, and built fountains and reservoirs.

[35] Based on the histories of al-Tabari (d. 923) and Agapius of Hierapolis (d. 941), the first raid of Mu'awiya's caliphate occurred in 662 or 663, during which his forces inflicted a heavy defeat on a Byzantine army with numerous patricians slain.

[170] An Arab fleet reached the Sea of Marmara by autumn, while Yazid and Fadala, having raided Chalcedon through the winter, besieged Constantinople in spring 668, but due to famine and disease, lifted the siege in late June.

[179] A thirty-year treaty was concluded, obliging the Caliphate to pay an annual tribute of 3,000 gold coins, 50 horses and 30 slaves, and withdraw their troops from the forward bases they had occupied on the Byzantine coast.

[186][188] In the last region he established a permanent Arab garrison town called Kairouan, at a relatively safe distance from Carthage and the coastal areas, which had remained under Byzantine control, to serve as a base for further expeditions.

The new Arab province, Ifriqiya (modern-day Tunisia), remained subordinate to the governor of Egypt, who sent his mawla (non-Arab, Muslim freedman) Abu al-Muhajir Dinar to replace Uqba, who was arrested and transferred to Mu'awiya's custody in Damascus.

[187] After Mu'awiya's death, his successor Yazid reappointed Uqba, Kasila defected and a Byzantine–Berber alliance ended Arab control over Ifriqiya,[189] which was not reestablished until the reign of Caliph Abd al-Malik ibn Marwan (r. 685–705).

[194][i] It was not until the latter half of his reign that Mu'awiya publicly declared Yazid heir apparent, though the early Muslim sources offer divergent details about the timing and location of the events relating to the decision.

[244] Mu'awiya was compared to these monarchs mainly because he appointed his son Yazid as the next caliph, which was viewed as a violation of the Islamic principle of shura and an introduction of dynastic rule on par with the Byzantines and Sasanians.

[239] According to Kennedy, the Nestorian Christian chronicler John bar Penkaye writing in the 690s "has nothing but praise for the first Umayyad caliph ... of whose reign he says 'the peace throughout the world was such that we have never heard, either from our fathers or from our grandparents, or seen that there had ever been any like it'".