First Fitna
Part of the Fitnas & Military career of Ali
Map of the Ali–Mu'awiya conflict of the First Fitna   Region under the control of Caliph Ali   Region under the control of Mu'awiya
Date c. 656–661 CE Location Arabia Syria Jazira Egypt Iraq Result Umayyad victory[1] Hasan–Mu'awiya treaty Dissolution of the Rashidun Caliphate Kharijites suppressed Establishment of the Umayyad Caliphate
Belligerents
Rashidun Caliphate	Umayyad Syria Uthmaniyya	Kharijites
Commanders and leaders
Ali X Hasan ibn Ali Husayn ibn Ali Muhammad ibn al-Hanafiyya Malik al-Ashtar X Ammar ibn Yasir † Muhammad ibn Abi Bakr †	Mu'awiya (WIA)[2] Aisha (POW) Talha † Zubayr X Amr ibn al-'As Marwan ibn al-Hakam (POW) Abd Allah ibn Amir Utba ibn Abi Sufyan	Abd Allah ibn Wahb  † Hurqus ibn Zuhayr † Abd al-Rahman ibn Muljam

The First Fitna (Arabic: الفتنة الكبرى) was the first civil war in the Islamic community. It led to the end of the Rashidun Caliphate and the establishment of the Umayyad Caliphate. The civil war involved three main factions; the supporters of the fourth Rashidun caliph Ali, the supporters of Uthman, primarily led by Mu'awiya and Aisha, and the Kharijites.

The roots of the first civil war can be traced back to the assassination of the second Rashidun caliph, Umar. Before he died from his wounds, Umar formed a six-member council which elected Uthman as the next caliph. During the final years of Uthman's caliphate, he was accused of nepotism and killed by rebels in 656. After Uthman's assassination, Ali was elected as the fourth caliph. Aisha, Talha, and Zubayr opposed Ali's accession and revolted against Ali to depose him. The two parties fought the Battle of the Camel in December 656, from which Ali emerged victorious. Afterwards, Mu'awiya, the long-time governor of the Levant, refused to recognise Ali as caliph and declared war. The two parties fought the Battle of Siffin in July 657, which ended in a stalemate and arbitration.

This arbitration was resented by the Kharijites, who declared Ali, Mu'awiya, and their followers to be infidels. Following Kharijite violence against civilians, Ali's forces crushed them in the Battle of Nahrawan. Soon after, Mu'awiya also gained control of Egypt with the aid of Amr ibn al-As.

In 661, Ali was assassinated by the Kharijite Abd al-Rahman ibn Muljam. After Ali's death, his eldest son and heir Hasan was chosen as caliph in Kufa. Mu'awiya quickly marched on Kufa with a large army. The embattled Hasan concluded a peace treaty, acknowledging the rule of Mu'awiya, who subsequently founded the Umayyad Caliphate and ruled as its first caliph.

Following Muhammad's death in 632, Abu Bakr became the leader of the Muslim community. After reasserting Muslim control over the dissident tribes of Arabia, he sent armies to fight against the empires of Byzantium and Sasanian Persia, initiating a wave of conquests which were continued by his successor Umar (r. 634–644). These battles brought about the near-total collapse of the Sasanians, and restricted the Byzantine Empire to Anatolia, North Africa, and its holdings in Europe.^[3] The conquests brought Muslims bounteous revenue and lands.^[4] In Iraq, the lands of the Persian crown and aristocracy were now in Muslim hands. These became state-administered communal property. The revenue was distributed among the conquering troops, who settled in Iraq.^[5] Umar also left provincial administration to regional governors, who ruled with considerable autonomy. Provincial surplus was spent on the Muslim settlers of the conquered territories rather than forwarded to the capital at Medina.^{[6][full citation needed]}

Uthman succeeded Umar upon the latter's assassination by a slave in 644. The new caliph's policies elicited discontent among the Muslim elite as well as accusations of nepotism. He began centralizing power by relying on his Umayyad relatives, who had long opposed Muhammad before converting to Islam in 630. His favor toward relatives was to the exclusion of other members of the Quraysh,^[a] who had enjoyed significant authority during the reign of his two predecessors. He appointed his kinsmen to nearly all of the important provincial governorships.^[7] Although Uthman continued Muslim expansion in Persia and Egypt, these conquests came to a halt by the latter half of his reign.^[8] The influx of spoils slowed, magnifying economic issues that had previously been tempered by incoming revenue.^[9] This was coupled with the antipathy of the Arab nomads towards central authority, which had hitherto been superseded by the continued war effort.^[10] The continued migration of Arab tribes from the Peninsula to the conquered territories also resulted in reduced payments from the revenue of the lands, which led to resentment among the earlier settlers.^[11] Early settlers also saw their status threatened by land grants in the conquered territories to prominent Qurayshites like Talha ibn Ubayd Allah and Zubayr ibn al-Awwam, as well as land acquisitions by late-arriving tribal chiefs, such as Al-Ash'ath ibn Qays. These chiefs were given this territory in exchange for their lands in Arabia.^[12] Furthermore, Uthman took control of the crown lands of Iraq as state assets and demanded that the provincial surplus be forwarded to the caliph. This interference in provincial affairs brought about widespread opposition to his rule, especially from Iraq and Egypt, where the majority of the conquering armies had settled.^[13]

Encouraged by the disaffected Muslim elite in Medina including prominent figures like Talha, Zubayr, Amr ibn al-As (the conqueror and former governor of Egypt who Uthman deposed in favour of his foster brother), and Muhammad's wife Aisha, the provincial opposition subsequently broadened into open rebellion. Dissidents from Egypt and Iraq marched on Medina, killing the caliph in June 656.^[14] Ali, Muhammad's cousin and son-in-law, was subsequently recognized caliph.^[15]

Aisha, Talha, and Zubayr opposed Ali's succession and gathered in Mecca, where they demanded vengeance for Uthman's death and the election of a new caliph, presumably Talha.^[16] The rebels raised an army and captured Basra from Ali's governor, inflicting heavy casualties on his men, with the intention of strengthening their position.^[17] Ali sent his son Hasan to mobilize troops in Kufa.^[18] After Ali arrived in Kufa himself, the combined army marched to Basra.^[19]

The two armies met outside Basra. After three days of failed negotiations, the battle began in the afternoon of 8 December 656 and lasted until the evening.^[20] Zubayr left the field without fighting. Likely for the dishonorable act of leaving his fellow Muslims behind in a civil war he caused, Zubayr was pursued and killed shortly thereafter by Amr ibn Jarmuz, a man from the troops of al-Ahnaf bin Qays, a chief of the Banu Sa'd who had remained on the sidelines of the battle.^[21] Talha was killed by Marwan ibn al-Hakam, who was a kinsman and former secretary of Uthman, and a member of the Umayyad clan.^[22]

With the deaths of Talha and Zubayr, the fate of the battle was sealed in favor of Ali. However, the fight continued until Ali's troops succeeded in killing Aisha's camel, which her forces had rallied around. From this camel, the battle received its name.^[23] After admonishing Aisha, Ali sent her back to Medina, escorted by her brother.^[24] Ali also announced a public pardon and set the prisoners free.^[25] This pardon was also extended to high-profile rebels, including Marwan, who soon joined with his Umayyad kinsman Mu'awiya ibn Abi Sufyan, the long-time governor of Greater Syria, as a senior advisor.^[26]

Shortly after assuming power, Ali dismissed most governors whom he considered corrupt, including Mu'awiya, Uthman's cousin.^[27] Mu'awiya refused to step down and informed Ali through a representative that he would recognize Ali as caliph in exchange for the continued governorship of Syria, and possibly the annexation of Egypt.^[28] Ali rejected this proposal.^[29]

In response, Mu'awiya declared war on Ali on behalf of the Syrians, demanding vengeance for Uthman's death. The governor of Syria aimed to depose Ali and establish a new council in Syria to appoint the next caliph, who would presumably be Mu'awiya himself.^[30] Ali responded by letter that Mu'awiya was welcome to bring his case to Ali's court of justice, asking him to offer any evidence that would incriminate Ali in the murder of Uthman. Ali also challenged Mu'awiya to name any Syrian who would qualify for a new council.^[31]

Ali called a council of Islamic ruling elite which urged him to fight Mu'awiya.^[32] The two armies met at Siffin, west of the Euphrates, in 657 CE.^[33] There, the two sides negotiated for weeks.^[34] Notably, Mu'awiya repeated his proposition to recognize Ali in return for Syria, which was again rejected.^[35] In turn, Ali challenged Mu'awiya to a one-on-one duel to settle the matters and avoid the bloodshed. This offer was declined by Mu'awiya.^[36] The negotiations ceased without success on 18 July 657 and the two sides prepared for the battle.^[37] Fighting began on Wednesday, 26 July, and lasted for three or four days.^[38] By the final day, the balance had shifted in Ali's favor.^[39] When Mu'awiya was informed his army could not win, he decided to appeal to the Quran for arbitration.^[40] Before noon, Syrians raised copies of the book on their lances, shouting, "Let the book of God be the judge between us."^[41] Although Ali was suspicious of this appeal, his forces ceased fighting.^[42] Compelled by strong peace sentiments in his army and threats of mutiny, Ali accepted the proposal for arbitration.^[43]

The majority Kufans in Ali's army, who preferred autonomy, urged for the reportedly neutral Abu Musa al-Ashari as their representative. Ali considered Abu Musa politically naive but appointed him despite these reservations.^[44] In an agreement on 2 August, 657 CE, Abu Musa represented Ali's army while Mu'awiya's chief adviser, Amr ibn al-As, represented the other side.^[45] The two representatives committed to adhere to the Quran and Sunnah, and to save the Muslim community from war and division.^[46]

The two arbitrators met together, first at Dumat al-Jandal and then at Udhruh, and the proceedings likely lasted until mid-April 658 CE.^[47] At Dumat al-Jandal, the arbitrators reached the verdict that Uthman had been killed wrongfully and that Mu'awiya had the right to seek revenge.^[48] According to Madelung, this verdict was political rather than judicial, and a blunder of the naive Abu Musa.^[49] The verdict strengthened the Syrians' support for Mu'awiya and weakened the position of Ali as caliph.^[50]

The second meeting at Udhruh likely broke up in disarray when Amr broke his earlier agreement with Abu Musa.^[51] The Kufan delegation reacted furiously to Abu Musa's concessions, and the erstwhile arbitrator fled to Mecca in disgrace.^[52] Conversely, Amr was received victoriously by Mu'awiya on his return to Syria.^[53] After the conclusion of the arbitration in 659 CE, the Syrians pledged their allegiance to Mu'awiya as the next caliph.^[54] Ali denounced the conduct of the two arbitrators as contrary to the Quran and began to organize a new expedition to Syria.^[55]

Following the Battle of Siffin, a group separated from Ali when he agreed to settle the dispute with Mu'awiya through arbitration, a move considered by the group as against the Quran.^[56] Most of them had pressured Ali to accept the arbitration, but subsequently reversed course and declared that the right to judgment belonged to God alone.^[57] While Ali largely succeeded in regaining their support, the remaining opponents of arbitration gathered in Nahrawan, on the east bank of the Tigris.^[58] Due to their exodus, this group became known as the Kharijites, from the Arabic for "to go out" or "to rise in revolt".^[59][60]

The Kharijites elected Abd Allah ibn Wahb al-Rasibi as their new caliph. They denounced Ali's leadership, and declared him and his followers, as well as Mu'awiya and the Syrians, to be infidels. They also declared the shedding blood of such infidels to be licit.^[61] The Kharijites then began interrogating civilians about their views on Uthman and Ali, executing those who did not share their views.^[62] In one notable incident, the Kharijites reportedly disemboweled a farmer's pregnant wife, cutting out and killing her unborn infant, before beheading the farmer.^[63] Kharijites have been viewed as the forerunners of Islamic extremists.^[64]

Ali received the news of the Kharijites' violence and moved to Nahrawan with his army.^[65] There, he asked the Kharijites to surrender the murderers and return to their families.^[66] The Kharijites however, responded defiantly that they were collectively responsible for the murders.^[66] After multiple failed attempts at de-escalation, Ali announced an amnesty (that did not apply to murderers) and barred his army from commencing hostilities.^[67] The remaining Kharijites, estimated at 2,800, attacked and were vanquished by the vastly superior army of Ali. The injured, estimated at 400, were pardoned by Ali.^[68]

To consolidate his authority in Egypt, Ali appointed his foster son Muhammad ibn Abi Bakr, who was also the son of the first Rashidun caliph Abu Bakr, as his governor of Egypt.^[69][70] Muhammad's appointment proved unpopular, particularly amongst the supporters of Uthman, who gained support. This led to tensions between factions which supported Ali and those who sought revenge for Uthman’s death.

The Uthmanids, led by Yazid ibn al-Hārith who was bolstered by his ties to Muhammad's predecessor Qays ibn Sa'd, gathered at Kharbita. Muhammad ibn Abi Bakr first sent Al-Harith ibn Jumhan al-Ju‘fi to lead an offensive against them, but Al-Harith was killed in the engagement. He then dispatched Ibn Mudahim al-Kalbi in a second expedition, which also failed to defeat the Uthmanids.^[71]

As the conflict intensified and Muhammad failed to suppress the growing resistance of the local Uthmanids, Mu'awiya sought to carry out a military intervention in support of the Uthmanids and annex Egypt from Ali's control. The local Egyptian forces were split between the supporters of Ali, and the supporters of Uthman. Mu'awiya sent his Syrian forces, led by his top general Amr ibn al-As, to launch an offensive against Ali's loyalists. Amr, who was the conqueror of Egypt and its first Arab governor, gathered support from the local Uthmanids.

The Umayyad forces were documented to be around 6,000 troops, while the forces of Ali, led by Muhammad ibn Abi Bakr, were approximately 2,500. The military engagement resulted in the swift defeat of Ali's loyalists and the establishment of Umayyad authority over Egypt with Amr ibn al-As reinstated as its governor.^{[72][73][74][75]}

The second phase of the civil war consisted of a series of raids and military expeditions carried out by Umayyad forces in Hejaz, Yemen and Iraq after the failure of the arbitration talks following the Battle of Siffin. The campaigns against Ali's loyalists continued until the truce between Ali and Mu'awiya in 660.

Mu'awiya sent Zuhayr ibn Makhul to the desert of Al-Samawa, west of the Euphrates river, to collect taxes and extend his influence. In this region, most tribes belonged to the Banu Kalb, with whom Mu'awiya had a marital alliance through his wife Maysun bint Bahdal, who was the daughter of Bahdal ibn Unayf, the chief of the Banu Kalb. In response, Ali dispatched Al-Julas, Jafar and Ibn al-Ashbiyyah. The two sides clashed, and Jafar was killed by Zuhayr, with Al-Julas fleeing to Kufa and Ibn al-Ashbiyyah defecting to Mu'awiya after he was whipped by Zuhayr. The skirmish brought minor gains for the Umayyads.^[76]

Mu'awiya made an attempt to collect taxes from the neutral tribes of the region by dispatching Muslim ibn Uqba. However, their refusal led Ibn Uqba to besiege them, which Ali responded to by sending Malik ibn Ka'ab with 1000 cavalry to confront the Syrians. The battle was indecisive, and the Syrians retreated the next day.^[77][78]

When Mu'awiya dispatched Yazid ibn Shajara, he also sent Al-Harith ibn Nimr Al-Tanukhi to assert his authority in the region of Al-Jazira by taking captive those loyal to Ali. Al-Harith took seven men from Dara who had defected from Ali to Mu'awiya. They asked Mu'awiya to release their companions, but Mu'awiya rejected their request, and they consequently defected from him as well.

Mu'awiya wrote to Ali to ransom them with a man that Mu'aqqal ibn Qais had captured from the companions of Yazid ibn Shajara. Ali sent them to Mu'awiya, and Mu'awiya released those men. Ali sent Abd al-Rahman al-Khathami to pacify the region of Mosul. The defectors of the Taghlib tribe encountered Abd al-Rahman and killed him. Ali was prepared to send troops against the defectors, however, on the request of the Rabi'a tribe, who stated the killing of Abd al-Rahman as a mistake, Ali refrained from doing so. ^[79][80]

Al-Dahhak ibn Qays al-Fihri raided Al-Qutqutana, killing Ibn Umays. Ali asked the Kufans to rise up against the Syrian army. Hujr ibn Adi rose up first, following which 4,000 more people volunteered and set out to confront the attackers. They clashed with Al-Dahhak's forces in Palmyra, forcing him to retreat, after which raids continued for two more days. In the same year, Mu'awiya himself marched up to the Tigris River but later retreated.^[77][81][82]

After the Battle of Siffin, Mu'awiya dispatched Sufyan ibn Awf with 6000 troops to raid Al-Mada'in, Anbar and Hit.^[83] Sufyan first arrived in Al-Mada'in which was deserted and then went to Anbar, where 500 of Ali's troops were stationed; however only 100 troops remained in the battle. The two forces clashed in Anbar; but Ali's troops were unable to halt the Umayyad advance and were defeated with the chieftain Ashras ibn Hassan al-Bakri being killed alongside many others. After receiving the news, Ali rose on the pulpit and called for war against Sufyan's forces. Ali went up to Nukhayla himself until his followers pressured him to return. Sa'id ibn Qays al-Hamdani advanced to confront the forces of Sufyan ibn Awf with a force of 8000 troops and went as far as Anat.^[84][85][86]

Mu'awiya intended to overthrow Shabath ibn Rib'i, the governor of Nusaybin. Shabath had marched out to the outskirts of the city because he heard that a Syrian force planned to attack Hīt. He said, “Let us strike them before they strike us, for it is said: ‘Attack with a shout and they will flee.’”

Kumayl left only one man behind to guard Hīt and departed with all his companions. When the Umayyad army approached, the fifty men stationed in Hīt fled. Ali became angry when he heard this and wrote to Kumayl, saying:

“A man who neglects what he is responsible for and rushes into what is unnecessary is weak. But for you to abandon your duty and leave it for Qarqisiya is an error, ignorance, and bad judgment.”

Mu'awiya continued to launch repeated attacks on Qarqisiya. Around this time, Kumayl received a letter from Shabīb ibn ʿĀmir al-Azdī in Nasībīn. A spy had informed Shabīb that Mu'awiya had sent Abd al-Rahman ibn Qubath toward al-Jazīra, though it was unclear whether his destination was Hīt or the Euphrates region.

Kumayl consulted his men and said, “If Ibn Qubath is coming for us, we will meet him; and if he intends our brothers in Nasībīn, we will intercept him.” He then set out with 400 horsemen, leaving 600 men in Hīt, and began disrupting enemy movements.

Later, Kumayl appointed Abd Allah ibn Wahb al-Rasibi as commander in Hīt and went to join forces with Shabīb in Nasībīn. Shabīb brought 600 horsemen, and together they formed a force of 1,000 riders. They marched toward Abd al-Rahman ibn Qubath, who was at that time in Qarqisiya with a sizeable Syrian force.

Kumayl and Shabīb overtook the Syrian cavalry. The Umayyad forces, led by ʿAbd al-Raḥmān ibn Qubath and Ma'an ibn Yazid al-Salami, numbered about 2,400 men. A fierce battle ensued. The Syrian army was defeated with heavy casualties. Shabīb lost four of his men, while two of Kumayl’s soldiers,ʿAbd Allāh ibn Qays al-Qabīsī and Mudrik ibn Bishr al-Ghanawī, were killed.

After routing the Syrians, Kumayl instructed his men not to pursue the fleeing soldiers or kill the wounded. He said, “Do not chase them. We have already inflicted great harm. If we pursue them, they may regroup and return, and we do not know what outcome that would bring.” Kumayl then reported these events to ʿAlī ibn Abī Ṭālib, who prayed for him and praised his conduct.^{[87][88][89][90][91]}

When Shabib ibn Amir arrived with 600 horsemen from Nisibis, he found that the Syrians were routed by Kumayl, for which he congratulated him. Shabib went on to pursue the Syrians, and he crossed the Euphrates at Manbij, sending his cavalry to attack the region of Baalbek. When Mu'awiya ordered Habib ibn Maslama al-Fihri to confront Shabib, Shabib withdrew and raided the region of Raqqa. He looted cattle, horses and weapons from the city. Ali praised him for the successful raid but instructed him not to loot cattle or personal property except for horses and weaponry.^[92][93]

Mu'awiya dispatched Nu'man ibn Bashir with 2,000 troops to raid the garrison of Ayn Al-Tamr, which was stationed by Malik ibn Ka'ab Al-Arabi and his men. Ali asked the Kufans to respond to their assault, but their slow response prompted Ali to encourage the Kufans in a sermon to retaliate against the Syrians. Following this, Adi ibn Hatim went to Ali, offering 1,000 troops at his disposal. Adi, along with his 1,000 troops, under orders from Ali, went to al-Nukhayla and then from there, raided Syrian territory while moving along the Euphrates River.^{[94][page needed][95][96]}

After the death of Muhammad ibn Abi Bakr, Mu'awiya dispatched Abd Allah ibn Amir al-Hadhrami with 2,000 men to Basra to persuade its people, particularly the Banu Tamim, to join the Umayyads. ^[97] At the time, the governor of the city, Abd Allah ibn Abbas, had gone to Kufa, leaving Ziyad ibn Abihi as his deputy. Ziyad informed Ali about the deteriorating situation in the city. Forced to flee, Ziyad took refuge with the tribe of Azd.

Ali dispatched the Banu Tamim of Kufa under the command of Aʿyan ibn Dahiʿah al-Mujashiʿ to confront al-Hadhrami, but al-Mujashiʿ was killed shortly after arriving in Basra. Ali then sent Jariyah ibn Qudamah al-Saʿdi with a relief force of fifty men from the Banu Tamim. However, the tribesmen soon began fighting amongst themselves. Jariyah then called upon his deputy Ziyad and the Azd tribe for assistance. They arrived and skirmished with al-Hadhrami, forcing him to retreat and take shelter in the house of Sabil al-Saʿdi. The house was set on fire, killing most of the men inside. Those who escaped were cut down by the besieging forces.^{[98][94][page needed][99]}

Mu'awiya sent Yazid ibn Shajara, a pious Uthmanid, to secure the pledge of allegiance from the Quraysh tribe of Mecca in early 660, but the mission proved to be a failure. He was given an army of 3,000 soldiers, who were not informed about the objective of the expedition. Yazid refused to shed blood in the Islamic holy land, although Mu'awiya stated that removing the governor of Mecca (whom he considered to be a participant in the killing of Uthman) was a pious act.^{[94][page needed][100]} Later that year, Mu'awiya appointed Busr ibn Abi Artat in his plans to subjugate the Hejaz and Yemen regions.

Mu'awiya dispatched Abd Allah ibn Mas'ada al-Fazari to Medina and Mecca with 1,700 troops. Learning about this, Ali sent Al-Musayyab with 2,000 troops to counter him. The two forces skirmishes and Ibn Mas'ada was nearly captured, but he evaded capture, escaping to the fortress at Tayma which was besieged for three days by Al-Musayyab and his troops. The camels of Ibn Mas'ada's men were slaughtered by the tribesmen. Firewood was piled up at the fortress gates and set alight.

Ibn Mas'ada's men pleaded for mercy on the basis of tribal affiliations and the fire was extinguished. When Musayyab pulled back his forces, Ibn Mas'ada and his forces escaped to Syria under the cover of nightfall. A plan for pursuit was devised but Musayyab refused to pursue the escapees. For this act, Musayyab was demoted to alms collector, following a few days of imprisonment.^{[101][102][103][104]}

Amr ibn al-As provided Busr ibn Abi Artat with 3000 Syrian troops for his expedition. The Qaysi nobility warned Mu'awiya of the possible vengeance that Busr might exact on them in retaliation for the killings of Fihr and Kinana tribesmen by the Qaysi Banu Sulaym during the Conquest of Mecca, leading Mu'awiya to strip Busr of authority over the Qaysi tribesmen under his command. At Dayr Murran, he dropped 400 troops out of his campaign and continued his expedition with 2600 soldiers.^{[94][page needed][105]}

When Busr arrived in Medina, which was his primary target as it had been the capital of the caliphate before Ali relocated it to Kufa, he faced no resistance while delivering a speech condemning the Ansar, the traditional elites of Medina. Ali's governor of Medina, Abu Ayyub al-Ansari fled to Kufa. Busr halted at every watering place along his route and requested to use the camels of the locals when his soldiers were exhausted, in order to preserve the stamina of his war horses. He demolished the houses of Ali’s allies, including Abu Ayyub’s, and obtained the pledge of allegiance to Mu'awiya from the city’s notables, sparing its inhabitants.^[106][107]

After Medina, Busr headed towards Mecca, Ali's governor of city, Qutham ibn Abbas fled with a large number of its inhabitants. Following the execution of several notable Alid figures, Busr located the representative of Ali in the arbitration talks and a companion of Muhammad, Abu Musa al-Ash'ari, and pardoned him. After praying at the Ka'aba, Busr took pledges of allegiance to Mu'awiya from the inhabitants except from Sa'id ibn al-As, a distant kinsman of Mu'awiya. Qutham might have taken the control of Mecca after the departure of Busr from the city.^[107][108]

Al-Mughira ibn Shu'ba, one of the notables of Taif, greeted Busr when he had arrived at the city and persuaded him not to attack the Banu Thaqif. The representatives of Taif had also informed Busr that he had no authority over the core clan of Qays. Busr spared the inhabitants, while dispatching troops to Tabala against the partisans of Ali ibn Abi Talib, but ultimately pardoned them. After leaving Taif, Busr entered the tribal territory of the Kinana, where he came across Abd al-Rahman and Qutham, the young sons of Ubayd Allah ibn Abbas, governor of Yemen and Ali's cousin. Busr executed both Abd al-Rahman and Qutham.^{[109][110][111]} In 660, Mu'awiya sent Busr for the military campaign against Yemen which was being ruled by Ali's governor Ubayd Allah ibn Abbas.^[112]

Mu'awiya had imposed sanctions on Busr for his military expeditions in the Hejaz but did not place such terms in Yemen. Ka'b ibn Abda Dhi'l-Habaka al-Nahdi was executed by Busr for his previous criticism of Uthman. When he entered Najran, he ordered the execution of Abd Allah ibn Abd al-Madan, who was the leader of an embassy and his brother and son, Yazid and Malik respectively.

Busr first attacked the Arhab clan of the Banu Hamdan and killed many loyalists of Ali, which included Abu Karib, who was a chieftain of the Hamdan tribe. The Hamdan tribesmen took their positions above the mountains of Shibam and resisted Busr, who then bypassed the mountain and withdrew, however upon their return to the villages, Busr attacked them and captured their women. It was the first ever incidence of Muslims holding Muslim women as captives.^{[94][page needed]}

Ali's governors in Yemen, Ubayd Allah ibn Abbas and Sa'id ibn Nirman, fled to Kufa despite Sa'id's resistance to Busr's advance. Ubayd Allah's deputy in Sana'a, Amr ibn Araka al-Thaqafi, offered resistance to Busr's invasion but was killed by Busr along with many inhabitants. From Ma'arib, a delegation offered to submit to Mu'awiya, who were spared by Busr to spread the news of the massacre to the town.^[113] Busr then launched an offensive against Jayshan, where the support for Ali was strong. Many of Ali's partisans were killed and forced to withdraw to their forts, before retreating to Sanaa.^{[94][page needed]}

Shia sources state the total death toll inflicted by Busr in Yemen to have been around 30,000, however this is considered to be greatly exaggerated.^{[114][115][116][117][118][119]} In response, Ali had Busr cursed for his actions in the region, sent reinforcements to Yemen and criticized his governors there for not taking strong actions against the local Uthmanids.^{[120][121][122][123]}

Wa'il ibn Hujr invited Busr to Hadhramaut stating that half of the city was Uthmanid. Busr accepted the offer and was rejoiced by gifts, however upon Wa'il's query about Busr's intentions with the civilian population of the city, Busr replied that he intended to massacre a quarter of the city. Wa'il re-directed him to attack Abd Allah ibn Thawaba, a lord of Hadhramaut and Wa'il's rival. Busr executed Ibn Thawaba soon after.^{[94][page needed]}

Busr ended his expedition to Hadhramaut upon the news of a relief army sent by Ali and commanded by Jariya ibn Qudama and Wahab ibn Masud, consisting of 4000 troops. Busr then retreated to the Hejaz without confronting the relief army due to Mu'awiya's preference for minimal Syrian casualties. Upon his retreat, Busr did not punish the Banu Tamim who seized parts of his loot.^[124]

Busr entered Al-Yamama and decided to punish the chieftain of the Banu Hanifa for his neutrality in the civil war.^[107] His tribesmen were spared while the chieftain Mujja'a ibn Murara was killed and his son was taken captive, but who would later be freed by Mu'awiya and made the new chief of the Banu Hanifa tribe.^{[94][page needed]}

Upon the onslaught brought by Busr's expeditions in Yemen and the massacre of Ali's partisans in the region, Ali dispatched Jariyah ibn Qudamah and Wahb bin Masud with 2000 troops to engage Busr.^[125] Jariyah quickly approached Yemen with reinforcements, however the local Uthmanids started to flee upon their arrival and were ultimately persecuted and killed by Ali's partisans, while their properties were burned.^{[94][page needed][126]} During Busr's retreat, he was pursued by Jariyah to Mecca, which effectively restored Ali's control over Yemen. Mu'awiya, upon Busr's arrival to Syria, expressed his dissatisfaction with the outcome of the raids.^{[127][128][129]}

Jariyah marched to Mecca, where he asked the Meccans to pledge their allegiance to Ali. The Meccans informed him of Ali's death, upon which Jariyah urged them to give their allegiance to his eldest son and successor, Hasan ibn Ali. Despite being reluctant to do so, the Meccans later pledged their allegiance to Hasan.^{[130][131][132]}

Jariyah then arrived in Medina, where Abu Hurayra was leading the prayer, and asked the Medinans to pledge their allegiance to Hasan ibn Ali. The Medinans pledged their allegiance to Hasan and Jariyah stayed in Medina for a day, before returning to Kufa.^[133]

In late 660, an exchange of letters took place between Ali and Mu'awiya where both parties agreed to cease military campaigns and to partition the Caliphate with each side retaining the domains they controlled. This left Mu'awiya in control over the Levant, Egypt and the Jazira whereas Ali would rule over Iraq, Persia and Arabia.^[134] According to Abu Ishaq, when both parties refused to acknowledge the other, Mu'awiya wrote to Ali on one condition to which Ali agreed:

If you wish, you may have Iraq while I have Syria. Thus the sword shall be averted from this community and the blood of the Muslims shall not be shed. ^[135]

The partition resembled the territorial borders of the Roman and Persian Empires. The truce triggered a reaction from the Kharijites, who set up assassination plots against the leaders of both parties.^[136][137] Although they failed to assassinate Mu'awiya and Amr ibn al-As, in January 661, while praying at the Great Mosque of Kufa, Ali was assassinated by the Kharijite dissident Abd al-Rahman ibn Muljam, as revenge for the Kharijites killed at the Battle of Nahrawan.^[138]

After the assassination of Ali in January 661, his eldest son Hasan was proclaimed caliph in Kufa.^[139] Mu'awiya quickly marched on Kufa with a large army, while Hasan's military suffered defections in large numbers. These were facilitated by military commanders and tribal chiefs who had been swayed to Mu'awiya's side by promises of money and offers of amnesty.^[140] Hasan was wounded in a failed attempt on his life. By the time Hasan agreed to a peace treaty with Mu'awiya, his authority did not exceed the area around Kufa.^[141] Under this treaty, Hasan ceded the caliphate to Mu'awiya. The treaty stipulated a general amnesty for the people and that a council would choose the caliph after Mu'awiya's death.^[142] Mu'awiya was then crowned as caliph at a ceremony in Jerusalem.^[143]

• Mu'awiya I's Southern Campaigns (658–660)
• Kharijite Rebellions against Ali
• Umayyad invasions of Egypt (657–658)

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