There is a popular anecdote in Russia that a foreign-language encyclopedia (usually Petit Larousse) made a blatant mistake in one of its articles about the Russian Tsar Ivan IV (Ivan the Terrible).
The most popular version reads:
Один из самых забавных ляпов, который уже превратился в исторический анекдот, произошёл со знаменитым энциклопедическим словарём, издаваемым во Франции издательством «Ларусс». В издании 1903 года была напечатана статья про Ивана IV, в которой его знаменитое прозвище «Грозный» трактовалось несколько иначе. В ней было сказано: «Иван Четвёртый, Царь Всей Руси, прозванный за свою жестокость Васильевичем».
In English:
One of the most amusing blunders, which gave life to an anecdote, happened to the famous encyclopedic dictionary published by the French "Éditions Larousse". In its 1903 edition there was an article about Ivan IV, in which his famous nickname "The Terrible" was interpreted in a somewhat different way. The article read: "Ivan the Fourth, Tsar of All Russia, for his cruelty dubbed Vasilyevich"
(translation mine)
Of course Vasilyevich is not a nickname but rather a patronymic, an integral part of a Russian name, which makes this story very funny to a Russian-speaking person.
The closest match to a "1903 edition" mentioned by this article is the 1906's edition of "Le Petit Larousse" which is available online, but its article does not seem to say anything like that:
However, some versions of the anecdote don't mention the exact name or edition of the encyclopedia.
Was there an enyclopedia which made such a mistake?
If the whole story started as a joke, what could be its origin?