This cahier deals with the criticism of three sources: Dinawari's al-Akhbar al-Tiwal, the so-called Sirat Anusharwan, and Firdawsi's Shahnama. The need to examine these sources arises from a re-evaluation of Nöldeke's Khuday-Nama hypothesis; a case is built for the independence and utility of those three sources; and four test cases follow, in which the sources are put to work on issues of central importance in the history of sixth-century Iran. The conclusion is a narrative integrating the findings of the test cases into the broad picture of Sasanian history.