Recent travels in Central Asia introduced me to one of the most famous Uzbeks I never heard of: Mirzo Ulugbek – Uzbekistan’s “Great Observer”. He was an emir and mathematician, but it was as an astronomer that he made his mark.
Gurkhani Zij , Ulugbek’s observatory on the outskirts of Samarkand, is a unique historical monument, testament to the achievements of the Uzbek astronomer. There, for almost twenty years in the 15th century, he conducted celestial observations using a colossal quadrant mounted in a narrow, marble-lined slit in the ground. In Ulugbek’s time, the specially-built observatory was decorated with tiles; wall paintings inside represented the vault of the heaven, stars at their right locations, and the orbits of the planets.
Today, under a vaulted cover built in 1915, visitors can see fragments of parallel masonry bars, once covered with marble grooved for installing and moving astronomic instruments, lying within a 10-meter-deep trench. Stone stairs on either side of the bars were used by the medieval scientists of the observatory for performing measurements.
It is perhaps little wonder that many of Ulugbek’s contemporaries were taken aback upon contemplating the original instrument, at more than 30 meters in height. The observatory was demolished by religious extremists upon the astronomer-ruler’s death, and unearthed only at the beginning of the 20th century.
Ulugbek, a grandson of the Timur the Great (Tamerlane), became governor of Samarkand in 1409, at the tender age of sixteen. Two years later, he was sovereign ruler of the entire Mavarannahr khanate, and eventually ruled a large swath of Central Asia. 
With establishment of medressas in Samarkand and Bukhara, he transformed both cities into cultural centers of learning, inviting noted Islamic astronomers and mathematicians to study there. An inscription on the Bukhara medressa reads “It is the duty of every Muslim man and woman to acquire knowledge.”
In 1449, Ulugbek was assassinated by religious extremists, with the connivance of his son, bringing to a close a remarkable period of astronomic discovery. Fortunately, the star charts that established his scientific reputation survived.
Copies are kept in the observatory museum, built in 1970. Ulugbek is buried alongside his grandfather in Timur’s mausoleum in Samarkand.
