This is the first volume of a critical edition of the last of John Trevisa's major translations (previously unavailable in print). The De regimine principum, a Latin treatise on the education of princes, was composed originally for the French King Philip the Fair (1238-1314) and translated by Cornishman John Trevisa (c. 1342-1402), chaplain and man of letters to Thomas IV Lord Berkeley, a baronial representative in the deposition of the English King Richard II in 1399. The work comprises 182 folios of the Bodleian manuscript Digby 233, which is the only surviving copy of the translation-perhaps even copied and corrected from Trevisa's autograph. This edition will be of great value to scholars interested in the reception and transmission of De regimine principum, which with its nearly 300 known surviving manuscripts-55 of them having a medieval English provenance-in Latin and most European vernaculars, was one of the most popular and influential political/didactic works of the later Middle Ages. The second volume of this edition will explicitly place the text and its author within a larger historical and linguistic context and will include textual variants and a glossary.