Zoroastrianism originated in the area of modern Central Asia in the second millennium BCE among peoples speaking an ancient Iranian language. Its earliest forms are known from a corpus of texts which its followers much later referred to as Abestag (Avesta). By the time the oldest texts in the Avesta, the Gathas, and the Indic Vedas were composed in the second half of the second millennium BCE, the two communities had been separated for hundreds of years, and their religious ideas had taken different directions. The Avesta is a collection of mostly liturgical texts, known from manuscripts written between the thirteenth and nineteenth centuries. This chapter focuses on the Young Avestan tradition. In most of the manuscripts, the Avestan text is accompanied by a Pahlavi rendering with glosses, the zand. The standard elements of these texts are largely the same as those listed by Nagy for the Homeric Hymns.