Ulugh Beg ruled Samarkand, built a school there and measured the sky from an observatory. In October 1449 his own son had him killed. The two facts look like a story of science against violence. The sources tell a more political story.
This guide covers the man, his two madrasas, his observatory, his star catalogue and his death.
Who was Ulugh Beg?
His real name was Muhammad Taraghay. He was a Timurid ruler, mathematician and astronomer. His father was Shahrukh and his grandfather was Timur. His mother was Gevher Shad.
“Ulugh Beg” was a title. It was the Turkish form of the phrase amir-i kabir, “great amir”.
He was born on 22 March 1394 in Sultaniyya, a town in what is now Iran. In 1409 Shahrukh gave him the rule of Mawarannahr, the region centred on Samarkand. After Shahrukh died in 1447, Ulugh Beg became the Timurid sultan. He held that position until 1449.
Ulugh Beg Madrasa in Samarkand
If you stand on the Registan Square in Samarkand, one of the three buildings around you is his. The Ulugh Beg Madrasa was built between 1417 and 1420.
It was not only a religious school. Mathematics and astronomy were main subjects there. One of the leading teachers was Qadi Zada al-Rumi.
The UNESCO–IAU Astronomical Heritage portal dates the school to 1420. It says Ulugh Beg founded the observatory four years later.
Ulugh Beg Madrasa in Bukhara
The Bukhara madrasa is the older sibling. It was built in 1417. Its master builder was Ismail, son of Tahir of Isfahan.
The Bukhara State Museum-Reserve records the inscription over its gate. It declared that seeking knowledge is a duty for every Muslim man and woman.
The observatory in Samarkand
The observatory came after the school. The main instrument was the Fakhri sextant. It lay along the meridian and had a radius of about 40 metres. Part of it extended underground.
You can’t see the whole instrument today, but a part survives. The meridian arc that remains includes white marble plaques. Arabic letters and numerals are engraved on them.
The archaeologist Vasily Vyatkin found the lost site again in 1908.
Several scholars worked on the observing programme:
- Jamshid al-Kashi
- Qadi Zada al-Rumi
- Ali Qushji, who completed the programme
The catalogue and the tables
The work is called the Zij-i Ulugh Beg. It is written in Persian. It has four books, and the last one is about astrology.
The star catalogue holds 1018 stars. The first version was finished in 1437. Ulugh Beg did not simply shift Ptolemy’s values. He fixed star positions with new, independent measurements.
The second book contains tables of sine, cosine, tangent and cotangent. It also covers spherical astronomy and the calculation of the qibla, the direction of prayer.
You use the same idea when you open a compass app on your phone to find the direction of Mecca. Ulugh Beg’s tables solved that problem with numbers and a pen.
The Zij also computes the sine of 1°. It uses two methods, linked to Ulugh Beg and to al-Kashi. Both rest on solving a cubic equation.
The authorship of one related treatise is disputed. A treatise on computing the sine of one degree is attributed to Ulugh Beg through al-Birjandi. Most manuscripts name Qadi Zada al-Rumi as the author.
The catalogue travelled far. In 1665 Thomas Hyde published it in Oxford. He included the star names in Persian and Latin.
Ulugh Beg’s death: why did his son kill him?
The son was Abd al-Latif. In spring 1449 he rebelled. The sources that explain this revolt list his father’s neglect and humiliating treatment of him.
Encyclopaedia Iranica points to other likely factors as well. They include disputes over the tamgha tax and over the father’s interference in the princes’ finances. It does not present these as one settled cause.
Abd al-Latif also abolished customs duties on the India trade route. That cost the treasury income. He then raised an army against his father.
The armies met near the Oxus (Amu Darya). Ulugh Beg then pulled back. Men were deserting his army, and Samarkand was in turmoil. After his final defeat near Samarkand, he surrendered to his son.
The account relayed by Utrecht University says what happened next. Abd al-Latif gave his surrendered father permission to go on the hajj. Behind his back, he obtained a death fatwa. Then he had Ulugh Beg killed near Samarkand.
The date is debated. Utrecht University gives 27 October 1449 on the basis of the tomb inscription. It notes that some sources place the death two days earlier.
Is this a case of a ruler killed for studying stars? The sources do not show that. They show a dynastic struggle, a humiliated son and a quarrel over money. Blaming hatred of science alone is not well supported.
The killing did not end the violence. A few days after Ulugh Beg died, Abd al-Latif had his own brother Abd al-Aziz killed. On 8 May 1450 emirs loyal to Ulugh Beg killed Abd al-Latif.
Timeline
- 22 March 1394: Born in Sultaniyya.
- 1409: Shahrukh gives him the rule of Mawarannahr, centred on Samarkand.
- 1417: The Bukhara madrasa is built, and the Samarkand madrasa is begun.
- 1420: The Samarkand madrasa is finished.
- 1424: The observatory is founded, by the UNESCO–IAU portal’s dating.
- 1437: The star catalogue is finished in its first form.
- 1447: He becomes Timurid sultan after Shahrukh.
- Spring 1449: Abd al-Latif rebels against him.
- October 1449: He is killed near Samarkand. Sources give 25 or 27 October.
- 8 May 1450: Abd al-Latif is killed.
- 1665: Thomas Hyde publishes the catalogue in Oxford.
- 1908: Vyatkin finds the observatory site again.
Details you won’t find in guidebooks
- The last of the Zij’s four books is about astrology, not astronomy.
- Al-Kashi wrote letters to his father. They describe Ulugh Beg doing complex astronomical calculations on horseback.
- A white jade jug in the Gulbenkian Museum is dated 1447–1449. It carries Ulugh Beg’s name. The Mughal emperors Jahangir and Shah Jahan added their names later.
- The Bukhara gate inscription addresses women as well as men. It says learning is a duty for both.
FAQ
How did Ulugh Beg die?
He surrendered to his son Abd al-Latif after a final defeat near Samarkand. According to an account relayed by Utrecht University, Abd al-Latif granted him permission to go on the hajj, issued a death fatwa without his knowledge, and had him killed near Samarkand in October 1449.
On which date did Ulugh Beg die?
The inscription on his tomb gives 27 October 1449. Some sources place his death two days earlier, on 25 October.
When was the Ulugh Beg Madrasa in Samarkand built?
It was built between 1417 and 1420 on the Registan Square. Mathematics and astronomy were among its main subjects.
Who built the Ulugh Beg Madrasa in Bukhara?
It was built in 1417. The master builder was Ismail, son of Tahir of Isfahan.
What did Ulugh Beg’s observatory contain?
Its main instrument was the Fakhri sextant, a meridian instrument with a radius of about 40 metres, part of it underground. The surviving meridian arc has white marble plaques engraved with Arabic letters and numerals.
Sources
- TDV İslâm Ansiklopedisi — Uluğ Bey islamansiklopedisi.org.tr
- TDV İslâm Ansiklopedisi — Zîc-i Uluğ Bey islamansiklopedisi.org.tr
- Vikipedi — Uluğ Bey tr.wikipedia.org
- Uzbekistan official tourism portal — The Ulughbek Madrasah uzbekistan.travel
- Bukhara State Museum-Reserve — Ulugh Beg Madrasa bukharamuseums.uz
- Benno van Dalen, The Biographical Encyclopedia of Astronomers (McGill University) islamsci.mcgill.ca
- UNESCO–IAU Astronomical Heritage Portal — Ulugh Beg’s observatory web.astronomicalheritage.net
- Early Astronomy at the University of Michigan — Work of the Observatory early-astronomy-um.org
- Encyclopaedia Iranica — ʿAbd-al-Laṭīf Mīrzā iranicaonline.org
- Utrecht University — Biography of Ulugh Beg webspace.science.uu.nl
- Utrecht University — The Samarkand Observatory and Astronomical School of Ulugh Beg webspace.science.uu.nl
- Calouste Gulbenkian Museum — Jade jug gulbenkian.pt
Image: Ulugh Beg, Timurid painting 1425-50.jpg — Unknown artistUnknown artist, Public domain
