Korean History

Korean has been a monarch since a long time ago. There are Gojoseon (고조선), Goguryeo (고구려), Silla dynasty (신라국), Goryeo dynasty (고려국), Joseon dynasty (조선국), until Korean Empire (대한제국). Also, Buyeo (부여), Baekje (백제), Gaya Confederacy (갸야국), Tamna island (탐라국), Balhae (발해), Hubaekje (후백제), and Hugoguryeo (부고구려). The rulers always different all the time by periods.

Hubaekje

Gyeon Hwon and Gyeon Singeom.

Hugoguryeo

Gung Ye.

Silla: 

Hyeokgeose, Namhae, Yuri, Talhae, Pasa, Jima, Ilseong, Adalla, Beolhyu, Naehae, Jobun, Cheomhae, Michu, Yurye, Girim, Heulhae, Naemul, Silseong, Nulji, Jabi, Soji, Jijeung, Beopheung, Jinheung, Jinji, Jinpyeong, Q.Seondeok, Q.Jindeok, Taejong Muyeool, Munmu, Sinmun, Hyoso, Seongdeok, Hyoseong, Gyeongdeok, Hyegong, Seondeok, Wonseong, Soseong, Aejang, Heondeok, Heungdeok, Huigang, Minae, Sinmu, Munseong, Heonan, Gyeongmun, Heongang, Jeonggang, Q.Jinseong, Hyogong, Sindeok, Gyeongmyeong, Gyeongae, Gyeongsun.

Goryeo: 

Taejo, Hyejong, Jeongjong (I), Gwangjong, Gyeongjong, Seongjong, Mokjong, Hyeonjong, Deokjong, Jeongjong (II), Munjong, Sunjong, Seonjong, Heonjong, Sukjong, Yejong, Injong. Uijong, Myeongjong, Sinjong, Huijong, Gangjong, Gojong, Wonjong, Chungnyeol, Chungseon, Chungsuk, Chunghye, Chungmok, Chungjeong, Gongmin, U, Chang, Gongyang.

Joseon:

Taejo, Jeongjong, Taejong, Sejong, Munjong, Danjong, Sejo, Yejong, Seongjong, Yeonsan-gun, Jungjong, Injong, Myeongjong, Seonjo, Gwanghae-gun, Injo, Hyojong, Hyeonjong, Sukjong, Gyeongjong, Yeongjo, Jeongjo, Sunjo, Heonjong, Cheoljong, Gojong.

Korean Empire:

Gojong and Sunjong.