The I Ching or Yi Jing (Chinese: 易經, Mandarin: [î tɕíŋ]), usually translated Book of Changes or Classic of Changes, is an ancient Chinese divination text that is among the oldest of the Chinese classics. Originally a divination manual in the Western Zhou period (1000–750 BC), the I Ching was transformed over the course of the Warring States and early imperial periods (500–200 BC) into a cosmological text with a series of philosophical commentaries known as the "Ten Wings". After becoming part of the Five Classics in the 2nd century BC, the I Ching was the subject of scholarly commentary and the basis for divination practice for centuries across the Far East, and eventually took on an influential role in Western understanding of East Asian philosophical thought.