The siege of Damascus by Louis VII of France was a critical episode in the Second Crusade, which spanned from 1147 to 1149. The Second Crusade was launched in response to the fall of the County of Edessa in 1144 to the Zengid dynasty under Imad al-Din Zengi. Recognizing the need for a renewed military effort, Louis VII and the German King Conrad III took up the mantle of leading a crusading expedition. Louis VII led his forces to Damascus, which was strategically significant as it offered a path to the interior of the Levant and control over vital trade routes.

The siege began in late July 1148 and involved an assembly of a diverse array of crusading forces, including soldiers from various European noble houses. The Christians initially besieged the city, attempting to undermine the defenses and starve the residents. However, the siege was hampered by disunity among the Crusaders and the strong defensive measures implemented by the city's governor, who was aided by reinforcements from the surrounding Muslim territories. In lieu of gaining significant ground, the Crusaders faced logistical challenges and a dwindling supply of resources.

Ultimately, the siege was unsuccessful, leading to a withdrawal of Crusader forces within weeks. The failure to capture Damascus was a major blow to Christian ambitions in the region, demonstrating the challenges of maintaining a united front among different factions and the effective resilience of Muslim forces. The aftermath of the siege highlighted the growing complexities of the Crusader states and the increasing strength of Muslim leaders, such as Nur ad-Din, who would later consolidate power in Syria and Egypt.