Tatishchev information[1][2] (Russian: Татищевские известия, romanized: Tatishchevskie izvestiya; Ukrainian: Татищевські звістки[a], romanized: Tatyshchevs'ki zvistky) is a group of historiographical texts written by Imperial Russian historian Vasily Tatishchev (1686–1750) and posthumously published in his book Istoriya Rossiyskaya (История Российская, "History of Russia", 1768 onwards), containing information that has no analogues in currently known historical sources.
[9] 'It is in connection with [the need for a critical approach to sources] that we find the extremely skeptical attitude of the historiographer [Nikolay Karamzin] toward the information in the chronicle of the "pseudo Ioakim" incorporated in the Istoriia Rossiiskaia of Tatishchev and toward other "Tatishchev information" (data found only in that historian) which Karamzin considered "inventions" and "fantasies".'
[10][2] They are texts of varying length, from one or two added words to large whole stories, including lengthy speeches of princes and boyars.
Historian Nikolay Karamzin of the 19th century was one of the earliest critics of Tatishchev's dubious claims around the Ioakim Chronicle and his various other doubtful texts, calling them "inventions" and "fantasies".
[12] Between 1962 and 1968, the Academy of Sciences of the Soviet Union published a critical edition of the Istoriya Rossiyskaya and other works of Tatishchev (some of them yet unpublished) for scholarly examination of the reliability of all his assertions.