Persian literature is literature that is written or expressed in Iran. Persian literature has a history of one thousand and one hundred years. Persian poetry and Persian prose are the two main genres in Persian literature. Some ancient books on non-literary subjects such as history, prayers and various sciences also have literary value and over time have been included in the class of classic works of Persian literature. Persian literature has its roots in the ancient literature of Iran, which was influenced by Avestan texts in the Sassanid period in Middle Persian and Parthian Pahlavi languages.