The Rashidun army () was the core of the Rashidun Caliphate's armed forces during the early Muslim conquests in the 7th century. The army is reported to have maintained a high level of discipline, strategic prowess and organization, granting them successive victories in their various campaigns.Britain and the Arabs: Contributors: JB Glubb - author. Publisher: Hodder and Staughton. Place of Publication: London. Publication Year: 1959. Page Number:34
In its time, the Rashidun army was a very powerful and effective force. The three most successful generals of the army were Khalid ibn al-Walid, who conquered Persian Mesopotamia and the Roman Levant, Abu Ubaidah ibn al-Jarrah, who also conquered parts of the Roman Levant, and Amr ibn al-As, who conquered Roman Egypt. The army was a key component in the Rashidun Caliphate's territorial expansion and served as a medium for the early spread of Islam into the territories it conquered.
Historical overview
According to Tarikh at Tabari, the nucleus of the early caliphate forces were formed from the Green Division (al-Katibah al-Khadra), a unit that consisted of early converts from Muhajirun and Ansar that marched on to conquer Mecca.
Ridda wars
Upon Muhammad's death, the Muslim community was unprepared for the loss of its leader and many experienced a profound shock. Umar was particularly affected, instead declaring that Muhammad had gone to consult with God and would soon return, threatening anyone who would say that Muhammad was dead. Abu Bakr, having returned to Medina, calmed Umar by showing him Muhammad's body, convincing him of his death. He then addressed those who had gathered at the mosque, saying, "If anyone worships Muhammad, Muhammad is dead. If anyone worships God, God is alive, immortal", thus putting an end to any idolising impulse in the population. He then concluded with a verse from the Quran: "Muhammad is no more than an apostle, and many apostles have passed away before him."
Troubles emerged soon after Abu Bakr's succession, with several Arab tribes launching revolts, threatening the unity and stability of the new community and state. These insurgencies and the caliphate's responses to them are collectively referred to as the Ridda wars ("Wars of Apostasy").
The opposition movements came in two forms. One type challenged the political power of the nascent caliphate as well as the religious authority of Islam with the acclamation of rival ideologies, headed by political leaders who claimed the mantle of prophethood in the manner that Muhammad had done. These rebellions include: that of the Banu Asad ibn Khuzaymah headed by Tulayha ibn Khuwaylid that of the Banu Hanifa headed by Musaylima those from among the Banu Taghlib and the Bani Tamim headed by Sajah that of the Al-Ansi headed by Al-Aswad Al-Ansi Omani rebels led by Laqeet bin Malik These leaders are all denounced in Islamic histories as "false prophets".
The second form of opposition movement was more strictly political in character. Some of the revolts of this type took the form of tax rebellions in Najd among tribes such as the Banu Fazara and Banu Tamim. Other dissenters, while initially allied with the Muslims, used Muhammad's death as an opportunity to attempt to restrict the growth of the new Islamic state. They include some of the Rabīʿa in Bahrayn, the Azd in Oman, as well as among the Kinda and Khawlan in Yemen.
At their heart, the Ridda movements were challenges to the political and religious supremacy of the Islamic state. Through his success in suppressing the insurrections, Abu Bakr had in effect continued the political consolidation which had begun under Muhammad's leadership with relatively little interruption. By the wars' end, he had established Islamic hegemony over the entire Arabian Peninsula.
Military expansions
After the Treaty of al-Hudaybiya in 628, Islamic tradition holds that Muhammad sent many letters to the princes, kings, and chiefs of the various tribes and kingdoms of the time, exhorting them to convert to Islam and bow to the order of God. These letters were carried by ambassadors to Persia, Byzantium, Ethiopia, Egypt, Yemen, and Hira (Iraq) on the same day. This assertion has been brought under scrutiny by some modern historians of Islam—notably Grimme and Caetani.Leone Caetani, Annali dell' Islam, vol. 4, p. 74 Particularly in dispute is the assertion that Khosrau II received a letter from Muhammad, as the Sassanid court ceremony was notoriously intricate, and it is unlikely that a letter from what at the time was a minor regional power would have reached the hands of the Shahanshah.Leone Caetani, Annali dell'Islam, vol. 2, chapter 1, paragraph 45–46
With regards to Persia, Muslim histories further recount that at the beginning of the seventh year of migration, Muhammad appointed one of his officers, Abd Allah ibn Hudhafa, to carry his letter to Khosrow II inviting him to convert:
There are differing accounts of the reaction of Khosrau II."Kisra", M. Morony, The Encyclopaedia of Islam, Vol. V, ed.C.E. Bosworth, E.van Donzel, B. Lewis and C. Pellat, (E.J.Brill, 1980), 185.
By span from the ascensions of Abu Bakar as caliph until his death, the Rashidun Caliphate expanded steadily; within the span of 24 years, a vast territory was conquered comprising Mesopotamia, the Levant, parts of Anatolia, and most of the Sasanian Empire.
Expansions during Abu Bakr's reign
Arab Muslims first attacked Sassanid territory in 633, when Khalid ibn al-Walid invaded Mesopotamia (then known as the Sassanid province of Asōristān; roughly corresponding to modern-day Iraq), which was the political and economic centre of the Sassanid state.
Expansions during Umar's reign
Abu Bakr was aware of Umar's power and ability to succeed him. His was perhaps one of the smoothest transitions of power from one authority to another in the Muslim lands. Before his death, Abu Bakr called Uthman to write his will in which he declared Umar his successor. In his will he instructed Umar to continue the conquests on the Iraqi and Syrian fronts.
Following the transfer of Khalid to the Byzantine front in the Levant, the Muslims eventually lost their holdings to Sassanid counterattacks. The second Muslim invasion began in 636, under Sa'd ibn Abi Waqqas, when a key victory at the Battle of al-Qadisiyyah led to the permanent end of Sassanid control west of modern-day Iran. For the next six years, the Zagros Mountains, a natural barrier, marked the border between the Rashidun Caliphate and the Sassanid Empire. In 642, Umar ordered a full-scale invasion of Persia by the Rashidun army, which led to the complete conquest of the Sassanid Empire by 651. Directing from Medina, a few thousand kilometres away, Umar's quick conquest of Persia in a series of well-coordinated, multi-pronged attacks became his greatest triumph, contributing to his reputation as a great military and political strategist.
The military conquests were partially terminated between 638 and 639 during the years of great famine in Arabia and plague in the Levant. During his reign the Levant, Egypt, Cyrenaica, Tripolitania, Fezzan, eastern Anatolia, almost the whole of the Sassanid Persian Empire including Bactria, Persia, Azerbaijan, Armenia, Caucasus and Makran were annexed to the Rashidun Caliphate. Prior to his death in 644, Umar had ceased all military expeditions apparently to consolidate his rule in recently conquered Roman Egypt and the newly conquered Sassanid Empire (642–644). At his death in November 644, his rule extended from present day Libya in the west to the Indus river in the east and the Oxus river in the north.
Historians estimate more than 4,050 cities were conquered during the reign of Umar.
Expansions during Uthman's reign
In 644, prior to the complete annexation of Persia by the Arab Muslims, Umar was assassinated by Abu Lu'lu'a Firuz, a Persian craftsman who was captured in battle and brought to Arabia as a slave.
Uthman ibn Affan, the third caliph, was chosen by a committee in Medina, in northwestern Arabia, in. The second caliph, Umar ibn al-Khattab, was stabbed by Abu Lu'lu'a Firuz, a Persian slave.; . On his deathbed, Umar tasked a committee of six with choosing the next caliph among themselves. These six men from the Quraysh, all early companions of the Islamic prophet Muhammad, were
Ali ibn Abi Talib Abd al-Rahman ibn Awf Sa'd ibn Abi Waqqas Uthman ibn Affan Zubayr ibn al-Awwam Talha ibn Ubayd Allah
Where they unanimously selected Uthman as the successor. During his rule, Uthman's military style was less centralised as he delegated much military authority to his trusted kinsmen—e.g., Abd Allah ibn Amir, Mu'awiya I and Abd Allah ibn Sa'd—unlike Umar's more centralized policy. Consequently, this more independent policy allowed more expansion until Sindh, in modern Pakistan, which had not been touched during the tenure of Umar.History of the Prophets and Kings (Tarikh al-Tabari) Vol. 04 The Ancient Kingdoms: pg:183.
Mu'awiya I had been appointed the governor of Syria by Umar in 639 to stop Byzantine harassment from the sea during the Arab-Byzantine Wars. He succeeded his elder brother Yazid ibn Abi Sufyan, who died in a plague, along with Abu Ubayda ibn al-Jarrah. Now under Uthman's rule in 649, Mu'awiya was allowed to establish a navy, manned by Monophysitic Christians, Copts, and Jacobite Syrian Christian sailors and Muslim troops, which defeated the Byzantine navy at the Battle of the Masts in 655, opening up the Mediterranean.
In Hijri year 31 (c. 651), Uthman sent Abd Allah ibn al-Zubayr and Abd Allah ibn Sa'd to reconquer the Maghreb, where he met the army of Gregory the Patrician, Exarch of Africa and relative of Heraclius, which is recorded to have numbered between 120,000 or 200,000 soldiers. The opposing forces clashed at Sabuthilag (or Sufetula), which became the name of this battle. Records from al-Bidayah wal Nihayah state that Abd Allah's troops were completely surrounded by Gregory's army. However, Abd Allah ibn al-Zubayr spotted Gregory in his chariot and asked Abd Allah ibn Sa'd to lead a small detachment to intercept him. The interception was successful, and Gregory was slain by Zubayr's ambush party. Consequently, the morale of Byzantine army crumbled and soon they were routed.
Some Muslim sources claim that after the conquest of northern Africa was completed by Muhammad ibn Jarir al-Tabari,See: History of the Prophets and Kings (Tarikh al-Tabari) Abd Allah ibn Sa'd continued to Spain. Spain had first been invaded some sixty years earlier during the caliphate of Uthman. Other prominent Muslim historians, like Ibn Kathir,See: Al-Bidayah wa al-Nihayah (Tarikh ibn Kathir) have quoted the same narration. In the description of this campaign, two of Abd Allah ibn Sa'd's generals, Abd Allah ibn Nafi ibn Husayn, and Abd Allah ibn Nafi ibn Abd al-Qays, were ordered to invade the coastal areas of Spain by sea, aided by a Berber force. They succeeded in conquering the coastal areas of Al-Andalus. It is not known where the Muslim force landed, what resistance they met, and what parts of Spain they actually conquered. However, it is clear that the Muslims did conquer some portions of Spain during the caliphate of Uthman, presumably establishing colonies on its coast. On this occasion, Uthman is reported to have addressed a letter to the invading force:
Although raids by Berbers and Muslims were conducted against the Visigothic Kingdom in Spain during the late 7th century, there is no evidence that Spain was invaded nor that parts of it were conquered or settled by Muslims prior to the 711 campaign by Tariq.
Abd Allah ibn Sa'd also achieved success in the Caliphate's first decisive naval battle against the Byzantine Empire, the Battle of the Masts.Ridpath's Universal History, Merrill & Baker, Vol. 12, New York, p. 483.