Ancient Greek medicine was a system of healing that emerged around the 5th century BCE. It was heavily influenced by the works of Hippocrates, often referred to as the "Father of Medicine," who emphasized observation and clinical practice. Greek physicians believed in the balance of the four humors—blood, phlegm, yellow bile, and black bile—as essential for health. The Greeks also made significant contributions to medical ethics and the practice of medicine. They established the Hippocratic Oath, which set standards for medical conduct. Additionally, the works of Galen further advanced medical knowledge, combining philosophy and science to understand anatomy and physiology.