The Nuttall Encyclopedia
A Tartar prince, grandson of Tamerlane; astronomy was a favourite study of his, and in the patronage of it he founded an observatory at Samarcand; after a reign of 40 years conjointly with his father and by himself, he was put to death by a son who had rebelled against him (1394-1449).
Wood, James, ed. Entry for 'Ulugh-Beg'. The Nuttall Encyclopedia. https://www.studylight.org/encyclopedias/eng/nut/u/ulugh-beg.html. Frederick Warne & Co Ltd. London. 1900.