Legal review of Siavash story in Shahnameh based on Principle of Criminal Fair Trial

The Shahnameh that wrote by Abolghasem Ferdowsi Tusi, an iranian poet, about one thousand years ago is not only a literary and simple book, but also an essential and fundemental part of Iranian culture and identity. Interpreting and analyzing this huge book by interdisciplinary approaches and using different knowledge; primarily, criminal science can lead to its revival providing the readers with profound insight. The legal ontology of the world of Shahnameh introduces the concepts and historical legal institutions of ancient Iran to us. The essay is mostly a review and understanding Iran's law history that lets us briefly review some aspects of criminal procedure in ancient Iran. In this regard, by interpreting of Siyavash's story, we have attempted to compare the principles of fair trial to Siyavash criminal process. We have studied the story by a narrow-minded approach based on interpreting the "Innocence principle", "unification of investigation procecution" and "Ordeal".