Whose discovery was the circulation of blood?

For about 1,400 years, doctors followed the ideas of Galen, who taught that blood was constantly produced by the liver and consumed by the body. William Harvey, physician to King James I and later Charles I, carried out careful dissections and experiments. He calculated that the heart pumps far more blood in an hour than the body could possibly make from food, so it must be recycled. He published his findings in 1628 in “De Motu Cordis” (On the Motion of the Heart and Blood). Harvey could not see capillaries, which Marcello Malpighi observed with a microscope in 1661, completing the picture.