The Battle of Ayn Shams marked a critical conflict during the First Qarmatian invasion of Egypt, which began in the late 10th century. The Qarmatians, a radical Islamic sect, aimed to undermine the authority of the Fatimid Caliphate and establish their own control in the region. Led by Jawhar al-Siqilli, the commander for the Fatimids, the battle took place near Cairo, in the suburb of Ayn Shams. Jawhar’s forces, despite facing a determined and well-equipped enemy, showcased superior strategies and resilience. The Qarmatians had previously inflicted severe disruptions across the landscape, threatening the Fatimid rule and causing widespread fear. At Ayn Shams, the Fatimid troops deployed tactics that capitalized on their advantages in mobility and logistics. In a fierce engagement, Jawhar's soldiers were able to repel the Qarmatians and destroy their forces at the city’s gates. This significant loss for the Qarmatians halted their advancement into Egypt and represented a turning point in the military engagements between the two groups. The aftermath of the battle illustrated the challenges faced by the Qarmatians in achieving their goals against the disciplined and organized Fatimid army. The victory solidified Jawhar's reputation as a capable leader and allowed the Fatimids to consolidate their power further, laying the groundwork for future expansions in the region.