History is often seen as a collection of objective facts, but not everything we “know” is true. Across centuries, deliberate falsehoods have been woven into the fabric of our shared past—crafted to advance political agendas, shape cultural identities, or elevate personal legacies. These myths, repeated until they became accepted truths, continue to influence our understanding of the world. In this article, we unveil 15 of the most notorious historical myths that were intentionally fabricated, revealing the motivations behind each and the consequences they left behind.