We generally believe that the first battle that took place in the Islamic history was a battle of Badr. This is a great misconception. The fact, however, is that the Muslims did conduct 8 raids against non-believers before the Batter of Badr.
Among these 8 raids, 4 were the ones in which the Prophet PBUH took part. Here is a list of those expeditions that Muslims conducted before the battle of Badr:
1-Sif Al-Baḥr platoon: It is also known as the expedition of Hamza ibn Abdul Muttalib. The Holy Prophet PBUH commanded Hamza ibn Abdul Muttalib to lead an army of 30-40 Muhajir and raid onto a caravan belonging to Quraish.
The raid was conducted in the month of Ramadan in 1 A.H. The battle did not take place as Majdi ibn ‘Amr al-Juhani made both Quraish and Muhajir disperse without fighting through peaceful talk.
2-Raid by Ubaydah ibn al-Harith: The second Islamic raid took place in 623 (1 A.H). The Prophet PBUH commanded Ubaydah Ibn Al Harith to head an army of 60 Muhajir and attack the caravan of Quraish.
The Quraish’ caravan was being led by Abu Sufyan consisting of 200 riders equipped with weapons. The caravan was returning from Syria and the Muslims attacked it from the well at Thanyat al Murra. No fight took place as Quraish did not approach to attack.
3-Al-Kharrar expedition: This expedition took place in 1 A.H. (623 C.E.). The raid was ordered by the Holy Prophet PBUH, yet like the above two mentioned raids; the Prophet PBUH did not take part in this raid as well.
4-The raid at Waddan: This raid is to be considered as the very first Ghazwa (the battle in which the Holy Prophet PBUH took part). The raid was conducted in 2nd A.H. (623 C.E.).
The Holy Prophet PBUH along an army of 70 believers reached Waddan on 12th of Rajab to encounter the Quraish. However, the Quraish had dispersed before the arrival of the army and thereby no fight took place.
5-The raid at the Buwat: Also known as the Patrol of Buwat is the second raid in which the Holy Prophet PBUH took part. The raid took place in 623 A.D (2 A.H).
Holy Prophet PBUH along an army of 200 believers reached Buwat to attack Quraish. The Muslim army stayed at the place for some time yet returned back without holding a fight.
6-The expedition to Badr: This is the third expedition before the battle of Badr in which Holy Prophet PBUH took part. The raid at Badr took place in 2 A.H.
The raid was conducted in reaction to Kurz ibn Jabir’s raid into the Muslims region. He stole away some camels and thereby 70 Muslims under the leadership of the Holy Prophet PBUH raided Badr.
7-Patrol of Zul Al-Ushairah: The Prophet PBUH led an army of 200 believers to invade a caravan of Quraish that was moving towards Syria under the leadership of Abu Sufyan.
The Prophet PBUH waited for the caravan at Al Ushairah. The battle did not take place as a peace agreement was signed between the Muslims and Banu Damrah.
8-The Nakhla raid: This was the very first successful raid conducted before the battle of Badr. The Holy Prophet PBUH did not take part in it and made Abdullah ibn Jahsh the commander of the Muslim army. The Muslim army consisting of 8-12 believers was able to successfully attack the enemy at the Nakhla.