Recruitment by examination during the Yuan dynasty constituted a very minor part of the Yuan administration. Hereditary Mongol nobility formed the elite nucleus of the government. Initially the Mongols drew administrators from their subjects. In 1261, Kublai Khan ordered the establishment of Mongolian schools to draw officials from. The School for the Sons of the State was established in 1271 to give two or three years of training for the sons of the Imperial Bodyguards so that they might become suitable for official recruitment.