The Provinces of Chōsen were: At the end of World War II in 1945, Korea was divided into Northern Korea and Southern Korea under trusteeship of the Soviet Union and the United States.
The peninsula was divided at the 38th parallel in 1945.
Both North Korea and South Korea upgraded cities to a level equal to a province, and these cities are sometimes counted along with provinces.
In 935, Goryeo conquered the remnants of Silla, and in 936, it conquered Later Baekje. Taejo expanded the country's territory by conquering part of the land formerly belonging to Goguryeo, in the northwest of the Korean peninsula, as far north as the Amnok River (Yalu River).
A wall was constructed from the Amnok River in the northwest to the Sea of Japan (East Sea of Korea) in the southeast, on the boundary between Goryeo and the northeastern Jurched territory.
Gwannae-do included the administrative districts of Yangju, Hwangju, Gwangju, and Haeju; Jungwon-do included Chungju and Cheongju; Hanam-do replaced Gongju; Gangnam-do replaced Jeonju; Yeongnam-do replaced Sangju; Sannam-do replaced Jinju; and Haeyang-do replaced Naju and Seungju; the three other new provinces were Yeongdong-do, Panbang-do, and Paeseo-do.
Finally, in 1009, the ten provinces were again redivided, this time into five provinces (Do) and two frontier districts (Gye; 계; In 1413, Korea (at that time called Joseon) was divided into eight provinces: Chungcheong, Gangwon, Gyeonggi, Gyeongsang, Jeolla, Hamgyŏng (originally called Yeonggil), Hwanghae (originally called P'unghae), and P'yŏngan. "Gwandong" is the name for the region as a whole, with "Yeongseo" denoting the western half of the province and "Yeongdong" the eastern half.