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 rebellious son, Abdul-Latif "Pidarkush"(killer of his own father), while on his way to Mecca for pilgrimage after being deposed. Born in Soltaniyeh near Zanjan, northwestern Iran, his father was Shahrukh, 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 in Mashhad adjacent to the shrine of Prophet Mohammad’s 8th Infallible Successor, Imam Reza (AS).
His seat of government was Samarqand (currently in Uzbekistan), where he built an observatory with the assistance of the famous Iranian astronomer, Ghiyas od-Din Jamshid Kashani. He also built the Ulugh Beg Madrasahs in Samarqand and Bukhara, transforming the cities into centres of learning. He ruled for almost half-a-century the present-day countries of Uzbekistan, Tajikistan, Turkmenistan, Kyrgyzstan, and southern parts of Kazakhstan – and for a while parts of Khorasan. He 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.