Shakespeare's comedy Love's Labour's Lost has perplexed scholars and theatergoers alike for over 400 years due to its linguistic complexity, obscure topical allusions and decidedly non-comedic ending. According to traditional scholarly interpretations, it is Shakespeare's "French" play, based on events and characters from the French Wars of Religion. This work argues that the play's French surface conceals a Russian core. It outlines a comprehensive interpretation of Love's Labour's Lost that is rooted in diplomatic and trade relations between Russia and Elizabethan England during the dramatic decades following England's discovery of a northern trade route to Muscovy in 1553. Drawing on original research of 16th-century sources in English, Latin and French, the text also surveys Russian sources that have been previously unavailable in translation. This analysis provides new explanations for some of the play's previously most enigmatic elements, such as its unconventional ending, the significance of its secondary characters, linguistic anomalies and the Masque of the Muscovites itself.