Marc Bloch's Jewish heritage profoundly influenced his groundbreaking historical scholarship, even as he consciously distanced himself from Jewish religious identity. Through biographical analysis and close reading of Bloch's major works, particularly *Strange Defeat* and *The Historian's Craft*, a complex portrait emerges of how Jewish intellectual traditions unconsciously shaped his humanistic historiography and emphasis on social analysis over elite political narratives. The tensions between Bloch's Alsatian Jewish background and his intense French patriotism, heightened by the legacy of the Dreyfus Affair, created an irreconcilable identity conflict that manifested in what can be characterized as "inauthentic" Jewish existence. His super-patriotism and eventual martyrdom in the French Resistance represented a tragic attempt to resolve this conflict through assimilation. Drawing on existentialist analysis and historical contextualization of French-Jewish relations, the research reveals how Bloch's denial of his Jewish intellectual roots ultimately diminished both his personal authenticity and his potential influence on French society. His story raises broader questions about the complex negotiations of Jewish identity and citizenship in modern Europe.