Muhajirun

Muhajirun (Arabic: المهاجرون‎‎ The Emigrants) were the first converts to Islam and the Islamic Prophet Muhammad's advisors and relatives, who emigrated with him from Mecca to Medina, the event known in Islam as The Hijra. The early Muslims from Medina are called the Ansar ("helpers").

About a month after Hamzah's unsuccessful attack in the first caravan raid, Muhammad entrusted a party of sixty Muhajirun led by Ubaydah to conduct another operation at a Quraysh caravan that was returning from Syria and protected by two hundred armed men. The leader of this caravan was Abu Sufyan ibn Harb. The Muslim party went as far as Thanyatul-Murra, a watering place in Hejaz. No fighting took place, as the Quraysh were quite far from the place where Muslims were in the offing to attack the caravan. Nevertheless, Sa`d ibn Abi Waqqas shot an arrow at the Quraysh. This is known as the first arrow of Islam. Despite this surprise attack, no fighting took place and the Muslims returned empty-handed. It is believed that Ubaydah was the first to carry the banner of Islam; others say Hamzah was the first to carry the first banner .

Sa`d ibn Abi Waqqas was ordered to lead the third raid. His group consisted of about twenty Muhajirs. This raid was done about a month after the previous. Sa'd, with his soldiers, set up an ambush in the valley of Kharrar on the road to Mecca and waited to raid a returning Meccan caravan from Syria. But the caravan had already passed and the Muslims returned to Medina without a fight.

The fourth raid, known as the invasion of Waddan, was the first offensive in which Muhammad took part personally with 70, mostly Muhajir,troops. It is said that twelve months after moving to Medina, Muhammad himself led a caravan raid to Waddan (Al-Abwa). The aim was to intercept the caravans of the Quraysh. The raid party did not meet any Quraysh during the raid.

...
Wikipedia