During the Goryeo Dynasty, metal movable typeprinting was invented by Choe Yun-uiin 1234.This invention made printing easier, more efficient and also increased literacy, which observed by Chinese visitors was seen to be so important where it was considered to be shameful to not be able to read.The Mongol Empirelater adopted Korea's movable type printing and spread as far as Central Asia. There is conjecture as to whether or not Choe's invention had any influence on later printing inventions such as Gutenberg's Printing press.When the Mongolsinvaded Europethey inadvertently introduced different kinds of Asian technology.During the Joseon period, the Turtle Shipwas invented, which were covered by a wooden deck and iron with thorns,as well as other weapons such as the bigyeokjincheolloe cannon(비격진천뢰, 飛擊震天雷) and the hwacha.The Korean alphabet hangulwas also invented during this time by King Sejong the Great.SportMain articles: Sport in South Koreaand Sport in North KoreaNorth Korea and South Korea usually compete as two separate nations in international events. There are, however, a few examples of them having competed as one entity, under the name Korea.While association footballremains one of the most popular sports in South Korea, the martial art of taekwondois considered to be the national sport. Baseballand golfare also popular.Taekwon-DoMain article: TaekwondoTaekwon-Do is Korea's most famous martial art and sport. It combines combat techniques, self-defence, sport and exercise. Taekwon-Do has become an official
Olympic sport, starting as a demonstration event in 1988(when South Korea hosted the Games in Seoul) and becoming an official medal event in 2000.The two major Taekwon-Do federations were founded in Korea. The two are the International Taekwon-Do Federationand the World Taekwondo Federation.HapkidoMain article: HapkidoHapkido is a modern Korean martial artwith a grappling focus that employs joint locks, throws, kicks, punches and other striking attacks like attacks against pressure points. Hapkido emphasizes circular motion, non-resisting movements and control ofthe opponent. Practitioners seek to gain advantage through footwork and body positioning to employ leverage, avoiding the pure use of strength against strength.SsireumMain article: SsireumSsireum is a traditional form of wrestling that has been practiced in Korea for thousands of years, with evidence discovered from Goguryeo of Korea's Three Kingdoms Period (57 BCEto 688). Ssireum is the traditional national sport of Korea. During a match, opponents grip each other by sash belts wrapped around the waist and the thigh, attempting to throw their competitor to the sandy ground of the ring. The first opponent to touch the ground with any body part above the knee or to lose hold of their opponent loses the round.