Catholic martyr of the 1801 persecution who wrote the Silk Letter; baptismal name Alexis

| Life | 1775 ~ 1801 |
| Era | 조선 후기 |
| Clan | 창원 황씨 |
Hwang Sa-yeong (黃嗣永, 1775-1801) was a Catholic of late Joseon from the Changwon Hwang clan, with courtesy name Deokso and baptismal name Alexis. A posthumous son of Hwang Seok-beom, a minor official at the Office of Diplomatic Correspondence, he was born in Ahyeon, Seoul. At sixteen in 1790 he passed the jinsa examination, and King Jeongjo is said to have summoned him and promised office at twenty. That year he married Jeong Nan-ju, daughter of Jeong Yak-hyeon, becoming a nephew-in-law of Jeong Yak-yong, and under his in-laws' influence he was baptized in 1791.
Giving up ancestral rites meant giving up an official career, but he held to his faith. He became an associate of the Chinese priest Zhou Wenmo and was active in the lay Myeongdohoe, and in 1798 moved to Seoul and let his home be used for meetings. When the persecution of 1801 broke out and Zhou, Jeong Yak-jong, Yi Seung-hun and others were executed, he fled Seoul and hid in a potters' kiln cave at Baeron in Jecheon, North Chungcheong. There he wrote on white silk a letter to Bishop Gouvea in Beijing describing the persecution and asking for help from the Qing court and Western ships: the Silk Letter, about 62 by 40 cm, in 122 lines and over 13,000 characters.
The letter never reached its recipient; he was arrested in September 1801 and executed by dismemberment outside Seosomun on 10 December. Its appeal for outside help has divided opinion ever since: the Church sees it as a plea for religious freedom and a martyrdom, while some scholars regard it as a dangerous move against the state. His family suffered heavily, and his wife Jeong Nan-ju was exiled to Jeju. Some writings call him a descendant of Hwang Hyeong, but the genealogy needs further confirmation.
The original of the letter was seized and kept at the Euigeumbu, later obtained by Bishop Mutel of Seoul, and is now known to be in Rome. The Korean Catholic Church remembers him among its martyrs, and Baeron in Jecheon, where he hid, became a place of pilgrimage. His case is still discussed as raising the questions of religious freedom and national security together.
He became a jinsa at sixteen and married the daughter of Jeong Yak-hyeon, making him a nephew-in-law of Jeong Yak-yong. He came to Catholicism through his in-laws.
Escaping the persecution, he hid in a cave at Baeron in Jecheon and wrote the Silk Letter, which describes the persecution, brief biographies of martyrs and a request for Qing intervention.
The Church sees a martyr while some scholars are critical of the request for foreign help. It is best read in the context of its time rather than judged one-sidedly.
The location of his grave was not confirmed. He is commemorated at Baeron Holy Ground in Jecheon.
His wife was Jeong Nan-ju, daughter of Jeong Yak-hyeon; details about children were not confirmed.