The prominent astronomer-king of the Timurid dynasty, Mirza Mohammad Taraghay Ulugh Beg

Compiled by: Syed Ali Shahbaz
On 9th of the Islamic month of Ramadhan in 853 AH, the prominent astronomer-king of the Timurid dynasty, Mirza Mohammad Taraghay Ulugh Beg, was killed by his own rebellious son, Abdul-Latif "Pidarkush", while on his way to Mecca for pilgrimage after being deposed. Born in Soltaniyeh near Zanjan in Iran, his father was Shahroukh, the son and successor of the fearsome Turkic conqueror, Amir Timur, while his mother was the cultured and religious Iranian lady, Gowharshad, the builder of the famous mosque adjacent to the shrine of Imam Reza (AS), in Mashhad.
His seat of government was Samarqand where he built the great Ulugh Beg Observatory with the assistance of the famous Iranian astronomer, Ghiyasoddin Jamshid Kashani. He also built the Ulugh Beg Madrasahs in Samarqand and Bukhara, transforming the cities into cultural center of learning. He ruled Uzbekistan, Tajikistan, Turkmenistan, Kyrgyzstan, southern parts of Kazakhstan for almost half a century, and for a time being parts of Khorasan as well. Ulugh Beg determined the length of the sidereal year as 365.2570370, making it more accurate than Copernicus' estimate. He also determined the Earth's axial tilt as 23.52 degrees, which remained the most accurate measurement for hundreds of years. In mathematics, he wrote accurate trigonometric tables of sine and tangent values correct to at least eight decimal places. The crater, Ulugh Beg, on the Moon, is named after him.