The first record of the name East Sea can be traced back to a description of King Dongmyeong of the Goguryeo Kingdom in "The History of the Three Kingdoms." The period corresponds to 37 B.C.
The name East Sea also appears on the epigraph of a monument in Jian, on the north side of mid-Amonkgang, northeast of China. King Jansu erected this memorial to his late father, King Gwanggaeto, in A.D. 414.
The appellation Sea of Japan first appeared in 1602 in a map dubbed "Mappamondo (Complete Map of the World)" by Matteo Ricci, an Italian Catholic missionary based in Beijing. Therefore, the name Sea of Japan was first used about 1,600 years after Koreans began calling the sea area, the East Sea.