Lorenzo Valla's 'The treatise of Lorenzo Valla on the Donation of Constantine' is a groundbreaking work that challenges the authenticity of the Donation of Constantine, a document that claimed to grant extensive power and territory to the Catholic Church from the Roman Emperor Constantine. Valla's meticulous analysis of the text exposes historical inaccuracies and forgeries, highlighting his humanist approach to scholarly inquiry. Written in a persuasive and critical tone, the book demonstrates Valla's exceptional skill in textual criticism and sheds light on the importance of source evaluation in historical research. This treatise not only questions the authority of the papacy but also paves the way for modern historiography. Through the lens of Valla's work, readers are encouraged to rethink traditional narratives and engage in rigorous intellectual examination.