Ulugh Beg

Ulugh Beg was a Timurid prince who built the best observatory in the world and was murdered by his own son two years after inheriting the throne. He was a grandson of Tamerlane, governed Samarkand from his teens, and was a better astronomer than ruler. The observatory he built there around 1420 was a three-storey building housing a meridian arc some forty metres in radius, sunk into a trench in the rock so that it could be read with a precision smaller instruments could not reach. Working with al-Kashi and Qadi Zada he produced the Zij-i Sultani, a star catalogue of 1,018 stars compiled from fresh observation rather than copied from Ptolemy - the first substantial one for nearly two thousand years - and a value for the sidereal year that is within about half a minute of the modern figure. He founded madrasas and taught in them. As a ruler he lost battles and revenue, and when he succeeded his father in 1447 the religious establishment and his eldest son Abd al-Latif both turned on him. He was sent on pilgrimage and beheaded on the road in 1449 on his son's order. The observatory was destroyed and its foundations were rediscovered in 1908. His catalogue reached Europe in the seventeenth century and was printed at Oxford in 1665, where its positions were still worth having. A crater on the Moon carries his name and the Soviet Union put him on stamps as a native scientist of Uzbekistan. His remains were exhumed in 1941 and the neck injury confirmed the manner of his death; the examination was carried out days before the German invasion.

• Lived: 1394 CE – 1449 CE
• Nationality: Timurid
• Roles: monarch, scientist