Deception in warfare dates back to early history. "The Art of War", an ancient Chinese military treatise, emphasizes the importance of deception as a way for outnumbered forces to defeat larger adversaries. Examples of deception in warfare can be found in Ancient Egypt, Greece, and Rome, the Medieval Age, the Renaissance, and the European Colonial Era. Deception was employed during World War I and came into even greater prominence during World War II. In modern times, the militaries of several nations have evolved deception tactics, techniques and procedures into fully fledged doctrine.