Following the Battle of Badr, in which Muhammad and the Muslims were victors, many of the leaders in the Quraysh (the main Arab tribe that ruled Mecca at the time) had been slain, and so they needed a new leader.
This new leader was a very angry Abu Sufyan who wished little else than to have his revenge against the prophet. Thus, having learned of the current situation in Medina from the Banu Nadir, a Jewish tribe in Medina (and the second Jewish tribe to eventually be expelled by Muhammad from the region), Abu Sufyan marched his army to the city. But rather than directly attempting to conquer Medina they settled in an area near by, hoping that Muhammad’s forces would be lured out, thus taking them away from Medina’s fortifications and putting them into the open.
Muhammad obliged but unlike the Battle of Badr this conflict led to a major defeat for his army. Muhammad’s forces had already dwindled in number after some of his allies retreated from the battlefield. There was also disobedience in his own ranks as some of his men abandoned their positions to look for spoils in a Meccan camp and were struck by a Meccan surprise attach. Many Muslims died and their army suffered greater losses than the Meccans which led them to retreat back to Medina.
The Battle of Uhud is a significant event in early Islamic history and is mentioned in numerous Islamic sources including the Quran (3:122, 3:152, 3:166–168), Sahih al-Bukhari (3:30:108 & 4:52:276), and Sahih Muslim (4:2050), Ibn Ishaq, and Ibn Kathir.