The article is dedicated to the recently discovered archival source “Journal des Théâtre. Russie. Chapitre VIII. Théâtre de Znamensky”, — a manuscript that tells us about the theatrical activity of the dilettante Praskovia Ivanovna Myatleva.  At the late 18th - early 19th. Myatleva was a famous amateur actor. Later, the Myatlevs’ theater in St. Petersburg became famous, but only brief references to it by contemporaries and historians have survived. The found manuscript provides information about this theater for the first time, describing its troupe and allows us to reconstruct the repertoire. At the same time, it also provides information about the Myatleva’s creative path: from amateur court performances at the Hermitage Theater to the idea of creating her own private troupe.