Other than literary and mythical values, Shahnameh is one of the most important sources in the history of ancient Iran, which comprehensively narrates Sasanid history in particular. Ferdowsi, trustworthily, rhymed narrations of Sasanid era, which embodies most of the details of historical events. Some iranologists insist on the historical aspect of Shahnameh, while others have considered Shahnameh as non-historical. The narration of Shiruya and Khosro Parviz’ s death, and expressing the bases of collapse in Shahnameh are very important, and Arabic-Persian prose sources have dealt with them. In this study, historical data and details of these sources have been assessed and analyzed, using the historical narration of shahnameh, and their similarities and differences have also been revealed. Ferdowsi has constantly been loyal to his source, and despite all the limitations in rythm, poetic language, and narrative-fictional framework, he has versified the details truatworthily and precisely. He hasn’ t altered the forms of names and, and names of places, according to the standard language of his time, and hence the names are closer to Khoday-nameh. Ferdowsi has recorded some people and dates, which others have neglected, or have recorded incorrectly. Also, the attitude present in Khoday-nameh has entered Shahnameh through a mediator, and has refined it from non-Iranian and caliphate-centered lookouts. Many other sources of data are also present in Shahnameh, and some data have been reported only in Shahnameh. This research can make the stand of Shahnameh more valid and prominent, and can be beneficial for other researches in the field.