발해

만주와 한반도 북쪽 지역에 698년부터 926년까지 있던 나라. 대조영이 고구려가 망한 뒤 698년에 고구려의 유민과 말갈족을 모아 세운 나라이다. ‘해동성국’이라 불릴 만큼 나라의 힘이 강했으나, 926년에 중국의 요나라에게 멸망하였다.

English: Balhae Kingdom — A country that existed from the year 698 to 926 in Manchuria and in the northern part of the Korean Peninsula; a country established by Dae Jo-yeong after the fall of the Goguryeo Kingdom by gathering the remaining people of the Goguryeo Kingdom and the Mohe tribes; although the country was so powerful that it was known as the "Flourishing Land in the East", it was defeated by the Khitans in 926.