Queen Sindeok of Koksan Kang Clan (Hangul/Hanja: 신덕고황후 곡산강씨(神德高皇后 谷山康氏; Born: 1356 - Died: 1396) is the second consort of King Taejo Yi Seong-gye, the Founder of Joseon Dynasty. She is the daughter of Kang Yoon-seong (강윤성/康允成), Internal Prince Sangsan (Sangsan Buwon-gun/상산부원군/象山府院君) and coming from Koksan Kang Clan which is originated from Sinch'ŏn County, Northern Hwanghae Province, DPRK. She is posthumously known as Empress Sunwon Hyeon-gyeong Sindeok, Empress Go of Korean Empire (순원현경신덕고황후/順元顯敬神德高皇后). Perhaps, I can say she was posthumously known as the Empress Sindeok after the establishment of Korean Empire by Emperor Gojong Gwangmu in 1897.
Adopting a custom from the Goryeo Dynasty, King Taejo had two wives -- one from his hometown in Jeonju, Northern Jeolla Province (Queen Sinui of Anbyeon Han Clan), and one from the nation's capital, Seoul (Queen Sindeok of Koksan Kang Clan). Queen Sinui died a year before Taejong took the throne but had six sons and two daughters during the time the two were married. A further policy from the Goryeo Dynasty was to have a son from the first queen named Crown Prince to take over the throne, but between his love for Queen Sindeok and some persuasion from Prime Minister Jeong Do-jeon he had Queen Sindeok's second son named as Crown Prince.
When Queen Sindeok died in 1396, King Taejo built her tomb close to the city's fortress, currently located within central Seoul's Jeong-dong, and had Heungcheonsa Temple constructed nearby as a place to pray and spend time while visiting his wife's grave. While the king was in mourning his prime minister, Jeong Do-jeon, plotted to kill the sons of Queen Sinui to smooth the transition to the rule of Queen Sindeok's second son and cement his own position within the court. Queen Sinui's fifth son, Yi Bang-won, heard the news and raided the palace -- killing Jeong Do-jeon and both of Queen Sindeok's sons (Yi Bang-beon and Crown Prince Yi Bang-seok) in an event known as the First Strife of Princes.
It's reported that King Taejo, upset over the fratricide and saddened by the loss of his second wife, retired from the court after naming Queen Sinui's second son, Yi Bang-gwa (later King Jeongjong), as his replacement. Yi Bang-gwa assumed the throne under the name King Jeongjong but had ruled for less than a year before his brother Yi Bang-won (the same brother who had killed Queen Sindeok's sons) attacked a contingent of the royal forces and later coerced the king to name him Crown Prince. Giving in to his younger brother's rising aspirations, Jeongjong eventually abdicated and Yi Bang-won ruled from 1400-1418 as King Taejong.
There are two tombs which named as Jeongneung in Seoul, the First is Jeongneung in Seongbuk-gu which contains Queen Sindeok's body while the Jeongneung in Gangnam-gu contains King Jungjong's body. The interesting point is these two tombs have different Hanja notaions: 貞陵 for Seongbuk Jeongneung and 靖陵 for Gangnam Jeongneung.
The specific location for Seongbuk Jeongneung is 116 Arirang Avenue 19th Street/Arirangno 19-gil, Jeongneung-dong, Seoul Seongbuk-gu. Her tomb is accessible by using KORAIL-Seoul Metro Line 4 to Station 418: Sungshin Women's University-Donam Station (성신여대입구-돈암역(誠信女大入口-敦岩驛/Seongshin-yeodae Ipgu-Donam Yeok: Entrance to Sungshin Women's University-Donam).