Establishment of Muslim Military Forces
Formation of the Islamic Army
During his stay in Mecca and propagation of Islam, the Holy Prophet acted only as a Divinely commissioned leader. His activities were restricted to guiding people and struggling against the idolaters. However, after he settled in Yathrib, his function included both religious and political leadership, because the social conditions had drastically changed in Medina and the Holy Prophet was taking great steps in founding a new society based on Islamic instructions. For this reason, he could clearly envisage the probable hardships and obstacles. As a farsighted political figure, he was constantly searching for proper political solutions. His convention of a brotherly treaty between two groups of Muslims; the initiation and completion of a general treaty; and the convening of a nonaggression pact with the Jews—all these were within his precautionary activities.
The Qur'¡nic texts carrying political and social orders that were revealed in Medina were all appropriate guidelines for the Holy Prophet's proceedings. Then, he was ordered to prepare for war and defense. Consequently, he decided to form a defense force. The establishment of such a force was significant because the Meccan unbelievers, who could no longer torture Muslims after the Holy Prophet's Hegira, might probably plot a military strike at the very center of Islam (i.e. Medina). For this reason, the Holy Prophet planned initial stages for the formation of an Islamic army so as to encounter any such probabilities. This army was initially very limited in human sources and military equipment. However, within a short time, it developed in both aspects. At the beginning of this army’s formation, garrisons dispatched for military operations or surveillance did not exceed sixty; and this number did not exceed two hundred at most. In the second year and the Battle of Badr, the number was a little more than three hundred. However, in the eighth year and during the Meccan siege, the number of the Islam's soldiers was nearly ten thousand well-equipped soldiers.
Thus, the trend of events showed that the Holy Prophet's predictions came true. Beginning with the second year, there were numerous conflicts and confrontations between the believers and the unbelievers. If Muslims had lacked the required military forces, they would have been completely wiped out by their enemies.
With the small number of the armed forces which the Holy Prophet had at his disposal, he prepared for a series of military operations which could not be considered full-fledged wars. In none of these maneuvers did any military confrontation occur. Examples of such expeditions were the following:
The 30-man strong expedition called °amzah ibn `Abd al-Mu§§alib in the eighth month of Hegira chased the caravan of Quraysh on their return to Mecca.
The 60-man strong expedition called `Ubaydah ibn al-°¡rith in the eighth month of Hegira prosecuted Ab£-Sufy¡n.
The 20-man strong expedition called Sa`d Ibn Ab¢-Waqq¡¥ in the ninth month of Hegira prosecuted the caravan of Quraysh but did not reach it. In the eleventh month of Hegira, the Holy Prophet, accompanied by a group of Muslims, chased the caravan of Quraysh up to the land of Abw¡ but no confrontation took place. During this expedition, he convened a treaty with the tribe of Ban£-®amrah according to which they promised to remain impartial and not to cooperate with the enemies of Islam. In Rab¢` al-Awwal (the twelfth month), the Holy Prophet chased Kurz ibn J¡bir al-Fahr¢, who had plundered a Medinan flock, up to the land of Badr but missed him. In the month of Jum¡d¡ al-ªkhir, the Holy Prophet, accompanied by one hundred and fifty (or two hundred) troops, chased the trade caravan of Quraysh, headed by Ab£-Sufy¡n on his journey to Damascus, but this time, he could not reach the caravan. However, during this time, he convened a treaty with the tribe Ban£-Mudlij and returned to Medina. These kinds of small military operations could be called military maneuvers and strength show, but not real wars.
 Permission to fight is given to those upon whom war is made because they are oppressed, and most surely Allah is well able to assist them; those who have been expelled from their homes without a just cause. (Qur'¡n, 22:39-40)
See al-M¢z¡n 14:383; T¡r¢kh Ya`q£b¢ 2:36.
 Ibn al-Ath¢r, Al-K¡mil f¢’l-T¡r¢kh 2:112.
 The number of the wars in which the Holy Prophet took part is said to be twenty-six, while expeditions were thirty-six. See Ibn Shahr¡sh£b, Man¡qib 1:186; ±abars¢, I`l¡m al-War¡, pp. 72.
Some historians have considered the number of such expeditions to be more than this number. See Mas`£d¢, Mur£j al-Dhahab 2:282.
Bukh¡r¢ recognizes this number to be nineteen. See ¯a¦¢¦ al-Bukh¡r¢ 6:327.
 al-W¡qid¢, al-Magh¡z¢ 1:9-11; al-±abar¢, T¡r¢kh al-Umam wa’l-Mul£k 2:259; Ibn Hush¡m, al-S¢rah al-Nabawiyyah 2:245, 251. Ibn Is¦¡q states that these expeditions took place in the second year of Hegira. (±abar¢: op cit). If we accept this, we have to set the date of the formation of the Islamic army at the second year of Hegira. This too, would not take away anything of the significance of the Holy Prophet's preventative procedures.
 al-W¡qid¢, op cit, pp. 11-13; ±abar¢, op cit, pp. 259-261.