Muslims and the Meccans (Makkans) met for the first battle in 624 CE, at Badr. At that time, Mecca (Makkah) was one of the richest and most powerful cities in Arabia fielding an army three times larger than that of the Muslims.
The battle began with an Arab tradition where each side sends out warriors to fight each other. Ali, the Prophet’s son-in-law and cousin, Hamza, the Prophet’s uncle, and Ubayda, a companion of the Prophet from his clan, represented the Muslims and defeated the Meccan warriors. The battle began and ended with a decisive victory for the Muslims.
The Muslim’s victory also signaled other tribes that a new power had arisen in Arabia and strengthened Muhammad’s position as leader of the Muslim community in Madina.