Imad ad-Din Zengi was a prominent Muslim military leader and the founder of the Zengid dynasty in the 12th century. He is best known for his role in the Crusades, where he successfully defended Muslim territories against the advancing Crusader states. Zengi ruled over Mosul and later Aleppo, and he was recognized for his strategic military skills and efforts to unite various Muslim factions. Zengi's most notable achievement was the capture of Edessa in 1144, which was a significant blow to the Crusaders and marked the first major victory for Muslims in the region. His leadership laid the groundwork for future Muslim leaders, including Saladin, who would continue the fight against the Crusaders.