Khwaday-Namag
Encyclopedia
The Khwaday-Namag was a Sasanian history text, now lost, imagined first by Theodor Nöldeke
to be the common ancestor of all later Arabic histories of the Sasanian Empire. It was supposed to have been first translated into Arabic by Abd-Allāh Ibn al-Muqaffaʿ (d. 757 AD), who had access to Sassanid court documents. According to Nöldeke's theory, the book itself was composed first under the reign of Khusraw Anushirvan, and redacted in the reign of the last Sassanid monarch Yazdegerd III (r. 632-651).
This view of Nöldeke's has recently been disproven.
Theodor Nöldeke
Theodor Nöldeke was a German Semitic scholar, who was born in Harburg and studied in Göttingen, Vienna, Leiden and Berlin....
to be the common ancestor of all later Arabic histories of the Sasanian Empire. It was supposed to have been first translated into Arabic by Abd-Allāh Ibn al-Muqaffaʿ (d. 757 AD), who had access to Sassanid court documents. According to Nöldeke's theory, the book itself was composed first under the reign of Khusraw Anushirvan, and redacted in the reign of the last Sassanid monarch Yazdegerd III (r. 632-651).
This view of Nöldeke's has recently been disproven.