Ulug Beg, The Astronomer King

Perhaps the heavens determined his enquiring nature by birthing Mohammed Taragai on 22 March 1394, during the vernal equinox. Tamerlane soon recognized his grandson's talents, for he named him Ulug Beg, 'grand duke', and took him on campaigns to the Caucasus and India. In 1404 Spanish ambassador Clavijo attended the ten-year-old's wedding feast; five years later, his father Shahrukh made him viceroy of Samarkand, lord of Transoxiana, while he ruled Persia from Herat. The young man's love of mathematics, history, theology, medicine, poetry and music gave the city a reputation for learning and culture that drew the Turkish astronomer Qazi Zadeh Rumi. Under this tutor Ulug Beg found his favourite science.

From 1424 to 1429 he ordered the construction of an observatory without equal in East or West, on a scale to ensure unprecedented accuracy and make Samarkand the stargazing capital of the 15th century. With a circle of experts Ulug Beg plotted the coordinates of 1,018 stars (the first such undertaking since Ptolemy), devised rules for predicting eclipses and measured the stellar year to within one minute of modern electronic calculations. Ever alert for flattery, he accepted no observations until honest debate secured agreement. His memory was exceptional-when a librarian reported his hunting logbook lost, Ulug Beg instantly dictated the full list of kills, almost to perfection, as the logbook proved when rediscovered.

Like Galileo two centuries later, he challenged religious orthodoxy with statements of bold secularity, even heresy: "Religions dissipate like fog, kingdoms vanish, but the works of scientists remain for eternity." Shahrukh ruled Herat as an ideal Muslim monarch, devout and strong, whereas his son's court revelled in the feasting, song and dance of Tamerlane's day. Ulug Beg was supported by the official clergy and built various madrassah and mosques, but he failed to diffuse the growing hostility and power of Sufic dervishes. On his father's death in 1447 events simply overtook the new head of the troubled Timurid realm, exposing him as lettered scholar, not decisive ruler.

Blamed for the unruly behaviour of his son Abdulaziz and defeated several times in battle, Ulug Beg was seized in October 1449 by his other son, Abd al-Latif. A secret court of dervishes dispatched him on a redeeming pilgrimage to Mecca. He had only reached a village outside Samarkand when he was beheaded with Abd al-Latifs connivance. The observatory was razed to the ground as the "cemetery of forty evil spirits", yet just six months later the severed head of the parricide was displayed on his father's madrassah.

Ulug Beg's fellow scientist Ali Kushji fled to Constantinople, where the martyred ruler's star atlas was published to great acclaim throughout the Muslim world. Although these tables became known in Europe only in the mid-17th century, superseded by Tycho Brahe's discoveries around 1600, the observatory was still being imitated in India in the 18th century. In 1994, Uzbekistan proudly celebrated the 600th anniversary of the birth of Mirza (learned) Ulug Beg by restoring the beautiful buildings that survive him.