Whose discovery explained the circulation of the blood?

William Harvey, an English physician, is credited with describing how blood circulates continuously through the body. In 1628 he published his findings in a groundbreaking Latin treatise on the motion of the heart and blood. Harvey showed that the heart acts as a pump and that blood moves in a closed circuit through arteries and veins. His work overturned older ideas from classical medicine and became a foundation of modern physiology. The circulation model remains one of the most important discoveries in medical science.