Al-Biruni

Abu Rayhan al-Biruni was born in Kath in Khwarazm and spent his first twenty-five years there before serving at the courts of Bukhara, Tabaristan and Gurganj.

Around 1000 he completed The Remaining Signs of Past Centuries on the calendars and chronology of ancient peoples, and he calculated the Earth's radius with remarkable accuracy by measuring from a mountaintop.

From 1017 he lived at the court of Mahmud of Ghazni and joined his Indian campaigns; his book on India made him a founder of Indology. A university and a town in Uzbekistan bear his name.