Nur ad-Din Zengi was a prominent Muslim leader and military commander during the 12th century. He ruled the Zengid dynasty and is best known for his efforts to unite Muslim territories against the Crusaders. His reign began in 1146 and lasted until his death in 1174, during which he expanded his influence in Syria and Mesopotamia. Nur ad-Din was also a patron of architecture and culture, contributing to the construction of mosques, hospitals, and schools. His leadership laid the groundwork for the rise of his successor, Saladin, who would later become famous for his role in the Crusades.