The term "Lydian" primarily refers to an ancient civilization that existed in what is now western Turkey. The Lydians are known for their rich culture, advanced economy, and significant contributions to trade. They are often credited with inventing coinage, which revolutionized commerce in the ancient world. Lydia was ruled by several notable kings, including Croesus, who is famous for his immense wealth. The Lydian language is part of the Anatolian branch of the Indo-European language family. The region's capital, Sardis, was an important center for trade and culture during its peak.