Ibn al-Nafis
ابْن النَّفِيس
First to describe pulmonary blood circulation — 300 years before Harvey
Ala al-Din Abu al-Hasan Ali ibn Abi al-Hazm al-Qarshi, known as Ibn al-Nafis, was a 13th-century Arab physician who first described the pulmonary circulation of blood — how blood flows from the heart to the lungs and back — 300 years before William Harvey.