The Battle of Badr (624 AD) was the first military victory of the prophet Muhammad. In 622 AD, Muhammad and his first Muslim followers emigrated from the city of Mecca to Medina.
This emigration followed increasing hostilities between the Meccans, who were pagans and polytheists, and Muhammad who taught and proposed quite a different religion. Now living in Medina (over 300 kilometers away), Muhammad and the Meccans fought several smaller conflicts. From his new base, Muhammad raided Meccan caravans couriering much needed goods to the city. In one case, the prophet learned that a wealthy caravan was on route to Mecca, and thus he organized a raiding party of about 300 Muslims who, under his own leadership, would assault it and take its goods. At the same time, however, the Meccans, angered by repeated raids on their caravans, sent an army to confront the Muslim raiders.
The opposing forces clashed in the Battle of Badr where Muhammad and his forces, outnumbered by roughly 3-1, came out the victors. It wasn’t a particularly large battle as there were only 300 Muslims and 1000 Meccan fighters, and casualties were minimal in number. However, this victory was hugely significant for Muhammad and the Muslims. At the time Mecca was one of the most powerful cities in Arabia, and they possessed an army much larger than the Muslims. The victory at Badr, which the Quran attributes to supernatural forces (3: 123-125) and God (8:17), gave the Muslims confidence in the prophet Muhammad, their God and religion, and their fighting forces.
The Battle of Badr is mentioned and/or referred to elsewhere in the Quran (see 3:13 and 8), the ahadith (Sahih al-Bukhari 4:53:359, 4:53:369 and Sunan Abu Dawud 14:2716), and by Muhammad’s earliest biographer Ibn Ishaq.