Abu l-Qasim Firdowsi Tusi (940–1020) or Ferdowsi (also transliterated as Firdawsi, Firdusi, Firdosi, Firdausi) was a Persian poet.  He is the author of Shahnameh ("Book of Kings"). This is the world's longest epic poem created by a single poet and the national epic of Greater Iran. Ferdowsi is celebrated as the most influential figure in Persian literature and one of the greatest in the history of literature.