Andrei Rublev (1966) IMDb
Andrei Tarkovsky (writer-director).
A Christian painter of religious icons in the early fifteenth century grows more skilled as the years pass, despite exasperation by bad disciples, envy, pagans and war. He witnesses Russian history and includes himself in it through his influential artwork of invariable serenity.
An epic medieval biopic. Tarkovsky co-write the script. It’s better with some knowledge of the setting and the man.
References here: Mother Joan of the Angels (1961).