Goryeo: 918–1392 Originally friendly with the Yuan Dynasty, but due to the outbreak of war, it is being utilized as a colony. During the period of Yuan intervention, kings began using the prefix 'Chung' (loyal) in their names starting in the 1200s to signify loyalty to Yuan. Its territory grew slightly after reclaiming land from the Khitans. TMI: Close with the Song Dynasty; Goryeo is Korea. Status: Currently at war.

Yuan Dynasty: 1206–1368 Initially friendly with Korea and did not treat it as a colony, but eventually colonized it. The only nation to completely erase China (Song Dynasty) from the map. Its own territory is massive. TMI: Yuan nearly unified Asia; Yuan is Mongolia. Status: Currently at war.

Song Dynasty: 960–1279 Engaged in maritime trade with Goryeo since the 900s–1000s. The Khitans, viewing this unfavorably, blocked trade between Song and Goryeo. Attacked by the Khitans since the 1000s and by the Mongols since the 1200s, it retreated to become the Southern Song before disappearing from the map. TMI: Founded by Zhao Kuangyin; Song is China. Status: Currently fallen, but at war.

Khitan: 916–1125 Fought the Goryeo-Khitan War, but was unable to invade again after Goryeo successfully defended with fewer than 5,000 troops. The Khitans were destroyed by the Yuan Dynasty in 1125. Most of Yuan's territory came from the Khitans. Even the Khitans could not defeat the Song and fell first. TMI: The nation that destroyed Balhae; Khitan is currently fallen. Status: Currently fallen, but at war.

Japan: 701–1854 Remained a neutral state during the Goryeo-Mongol and Goryeo-Khitan wars. It did not fall in 1854 but rather transformed through modernization. 701 marks the beginning of the name 'Japan' being used, not the founding of the nation. The founding year of Japan is 660 B.C. TMI: A nation that was not conquered by Yuan; Ancient Japan is Japan. Status: Neutral state.

Jurchen: 1115–1636 Emerging in 1115, they lived in Goryeo lands until the Khitans ceded Jurchen territory to Goryeo, leading to their decline. However, they were 'reincarnated' years later as the Later Jin and then the Qing Dynasty. Originally small, they grew over time. They were also once conquered by the Mongols. TMI: Jurchen became Qing, which is China; Jurchen is currently fallen. Status: Currently fallen, but at war.

China: 1949–Present Does not recognize the Jurchens as 'China.' The China established by Mao Zedong in 1949 survives to this day. Descendants of the Xia Dynasty. While the current state dates to 1949, Chinese history goes back to 2070 B.C. It is arguably the oldest nation in Asia. TMI: China exists now; China is the successor to the Jurchen and Song dynasties. Status: Currently observing; not yet born in this era.

Korea: 1948–Present Established in 1948 following the drawing of the 38th parallel. However, its history dates back to 2333 B.C., making it one of the oldest nations in Asia. It was divided by the armistice line due to the Korean War. TMI: Korea is not yet unified; Korea is the successor to Goryeo. Status: Currently observing; not yet born in this era.

Japan: 1854–Present Boasts a long history starting from 660 B.C. Its history is so vast there are claims many races originated from Japan. The name changed from Wa to Japan in 701. During the Imjin War in 1592, the term 'Wa' was used disparagingly. TMI: Japan is an island nation; Ancient Japan and Wa are Japan. Status: Currently observing; not yet born in this era.

Mongolia: 1368–Present With the end of the Yuan Dynasty and the Mongol Empire, it became a small nation surrounded by giants like Russia and China. It only seems small because of its neighbors; compared to Europe, it is larger than France or the UK. TMI: Mongolia is larger than France, the UK, or Spain; Mongolia is the successor to Yuan. Status: Currently observing; not yet born in this era.