Seoul was founded and settled in 18 BC as Wiryeseong (위례성) during the Baekje era (18 BC-660 AD); became Hanyang (한양) during the Koryo/Goryeo era (918-1392); became Hanseong (한성) during the Joseon/Chosun era and the Korean Empire (1392-1910); was re-named Keijo (경성) during the Japanese annexation of Korea (1910-1945); and took on its present name Seoul (meaning "capital city") following World War II and Korea's liberation.

To learn more about the history of Seoul, please visit the following weblink: 

https://www.seoulsolution.kr/en/content/3323

The History of Seoul