Nadir Shah was a Persian ruler who reigned from 1736 to 1747. He is best known for his military conquests, particularly the invasion of India in 1739, where he captured the city of Delhi and looted its treasures, including the famous Koh-i-Noor diamond. His reign marked the peak of Persian power in the 18th century. Nadir Shah's rule was characterized by his efforts to consolidate power and restore the Persian Empire. However, his harsh methods and heavy taxation led to widespread discontent. He was assassinated in 1747, which resulted in the fragmentation of his empire and a decline in Persian influence.