King Hyeonjong, previously known as Crown Prince Gyeongjik (Hanja: 顯宗王 [景直世子]; Born: 15 March 1641 – Died: 17 September 1675), born Yi Yeon (이연/李棩) was the 18th monarch of Joseon Dynasty, reigning from 1659 to 1675. His reign was mostly marked by heavy conflict among nation's political factions on various issues, especially on funeral issues. Hyeonjong was born in 1641 as the first son of King Hyojong and Queen Inseon of Deoksu Jang Clan, while his father was still in China as captive of Manchu Qing Dynasty; thus he was born at Shenyang (Manchu: Mukden, Korean: SeonYang), Liaoning Province, People's Republic of China - the Manchu capital before Qing Dynasty officially move its capital to Beijing after defeating Ming Dynasty in 1644. He returned to Korea in 1645 along with his father and became Crown Prince in 1651.
When King Hyojong died in 1659, Hyeonjong succeeded his father as the ruler of Joseon. The first issue during his reign was about his predecessor's funeral; The conservative Westerners faction and the liberal Southerners faction squared off about how long Queen Jangryeol, King Injo's second wife, should have to wear funeral garment according to the Confucian form of funeral. The Westerners, headed by Woo-am Song Si-yeol, contended that she needed to wear the funeral garment for only a year, while the Southerners and their leader Heo Jeok wanted a 3-year period. This conflict arose because there was no previous record about Confucian funeral requirements when somebody's second stepson who actually succeeded the family line dies. The Westerners wanted to follow the custom for a second stepson, while the Southerners thought Hyojong deserved a 3-year funeral since he actually succeeded King Injo in the royal line.
The final decision was up to young King Hyeonjong; He chose to enforce a 1-year period, which would keep the Westerners as the major faction. However, at the same time, Hyeonjong did not remove Heo Jeok from office of Prime Minister, in order to prevent the Westerners from threatening royal authority. The feud between the Southerners and the Westerners was highly intensified by funeral issue; Earlier, after the fall of the Greater Northerners in 1623, the Westerners and the Southerners formed political alliance under the leadership of King Hyojong, but on the funeral issue, both sides were intractable, leading to a greater probability of confrontations.
Hyeonjong at first maintained the balance of two factions by compromising between them with the 1 year period of the Westerners and keeping Southerner Heo Jeok as Prime Minister, and the two factions resumed a peaceful relationship temporarily. However in 1674, when Queen Inseon, Hyojong's wife and Hyeonjong's mother, died, the funeral issue came up again; The Southerners wanted Queen Jaeui to wear the funeral garment for one year while the Westerners preferred a nine-month period. This time Hyeonjong listened to the Southerners and selected their method, making the Southerners faction as major political faction over the Westerners. The funeral controversy continued even after Hyeonjong died in 1675, and it was settled by Hyeonjong's successor King Sukjong, who banned all debate about this troublesome issue. The controversy even affected the publishment of official history of Hyeonjong's era; at first it was written chiefly by Southerners but later it was revised by Westerner historians.
In 1666, during Hyeonjong's reign, after more than thirteen years of captivity, Dutchman Hendrick Hamel left Korea and returned to the Netherlands, where he wrote a book about Joseon Dynasty and his experience in Korea, which introduced the small kingdom to many Europeans.
Hyeonjong stopped Hyojong's insuperable plan of northern conquest, since the Joseon had become a tributary state of the Qing Dynasty. Furthermore, after a series victories against the Ming Dynasty, the Qing Dynasty had become too mighty to resist. However, Hyeonjong continued Hyojong's military expansion and reconstruction of the nation which was devastated from the Japanese Imjin Invasion (1592-1598) and Manchu Jeongmyo and Byeongja Invasions of 1627 and 1636. He also encouraged astronomy and printing. He also legally banned the marriage between relatives and also between those who share the same surnames. He died in 1675, and was succeeded by his son King Sukjong Yi Soon.
King Hyeonjong was buried at the Royal Tomb of Sungneung (崇陵), a part of the Donggureung Royal Tomb Cluster in 197 Donggureung Avenue/Donggureungno, Inchang-dong san 11-1 beonji, Guri City, Gyeonggi Province. He was posthumously known as King Hyeonjong Sohyu Yeon-gyeong Dondeok Suseong Sunmun Sungmu Gyeong-in Changhyo the Great (현종소휴연경돈덕수성순문숙무경인창효대왕/顯宗昭休衍慶敦德綏成純文肅武敬仁彰孝大王).