Mongols, modeled after the Mongol Khagan, however, this history of Ming universalism has been obscured and denied by historians who covered it up and presented the Ming as xenophobes seeking to expunge Mongol influence and presenting while they presented the Qing and Yuan as "universal" rulers in contrast to the Ming. A cavalry-based army modeled on the Yuan military was implemented by the Hongwu and Yongle Emperors. Hongwu's army and officialdom incorporated Mongols. Mongols were retained by the Ming within its territory. in Guangxi Mongol archers participated in a war against Miao minorities. Math, calligraphy, literature, equestrianism, archery, music, and rites were the Six Arts. At the Guozijian, law, math, calligraphy, equestrianism, and archery were emphasized by the Ming Hongwu Emperor in addition to Confucian classics and also required in the imperial examinations. Archery and equestrianism were added to the exam by Hongwu in 1370 like how archery and equestrianism were required for non-military officials at the 武舉 College of War in 1162 by the Song Emperor Xiaozong. The area around the Meridian Gate of Nanjing was used for archery by guards and generals under Hongwu. The Imperial exam included archery. Archery on horseback was practiced by Chinese living near the frontier. Wang Ju's writings on archery were followed during the Ming and Yuan and the Ming developed new methods of archery. Jinling Tuyong showed archery in Nanjing during the Ming. Contests in archery were held in the capital for Garrison of Guard soldiers who were handpicked. The Ming focused on building up a powerful standing army that could drive off attacks by foreign barbarians. Beginning in the 14th century, the Ming armies drove out the Mongols and expanded China's territories to include Yunnan, Mongolia, Tibet, much of Xinjiang and Vietnam. The Ming also engaged in Overseas expeditions which included one violent conflict in Sri Lanka. Ming armies incorporated gunpowder weapons into their military force, speeding up a development that had been prevalent since the Song. Ming military institutions were largely responsible for the success of Ming's armies. The early Ming's military was organized by the Wei-suo system, which split the army up into numerous "Wei" or commands throughout the Ming frontiers. Each wei was to be self-sufficient in agriculture, with the troops stationed there farming as well as training. This system also forced soldiers to serve hereditarily in the army; although effective in initially taking control of the empire,