Thaddeus Jeong In-hyeok ( ? -1801)
Thaddeus Jeong In-hyeok was born to a middle class family in Seoul and ran a drug store. He learned the catechism from Peter Choe Pil-je around 1790 and became a Catholic. From then on, he taught the catechism to his brothers and stopped performing the ancestral rites to follow the teaching of the Church.
Thaddeus Jeong was arrested with his brothers during the Sinhae Persecution in 1791 and they were taken to the Justice Ministry. Some of the faithful and his brothers surrendered under the severe punishment but Thaddeus Jeong stood firm and professed his faith in God. Then the officials sent him home for three days to give his family an opportunity to try to persuade him to change his mind.
When Thaddeus Jeong returned home, his eldest brother went to the Justice Ministry and promised saying, ‘None of our family will believe in the Catholic religion.` The authority believed him, and never summoned Thaddeus Jeong again.
Then Thaddeus Jeong regretted and repented his mistake and professed his faith in God more bravely than ever. He associated with Catholic friends and committed himself to Church activities. His family tried to stop him practicing his religion to persuade him to renounce his faith in God, but it was in vain. He formed a community of the faithful with Thomas Choe Pil-gong and Barnabas Kim Yi-u and devoted himself to studying Catholic doctrine with zeal.
When Father James Zhou Wen-mo, a Chinese priest, came to Korea at the end of 1794, Thaddeus Jeong visited him, attended Mass, and received the Sacraments. He joined the Myeongdohoe, a community of lay believers that father James Zhou had established, and taught the catechism to the faithful. He also distributed religious books, translated into Korean, to the faithful.
Soon after the shinyu persecution broke out in 1801 Thaddeus Jeong was arrested again with other Catholics for his involvement in Church activities. He was interrogated and tortured severely at the Police Headquarters and the Justice Ministry, but said nothing that would do harm to the Church or to the faithful, but professed only to his faith in God.
On May 14, 1801 (April 2, by the Lunar calendar) he was taken outside the Small West Gate in Seoul with Peter Choe, beheaded and died a martyr. The written death sentence on Thaddeus Jeong declared by the Justice Ministry reads as follows:
"You are so deeply imbued with the Catholic religion that you failed to correct your evil conduct. Besides, you invited a priest on the seventh day of every month to have Mass with the other faithful. You learned Catholic books by heart and guided people in evil ways, as a result you deluded the entire world. Your many sins deserve death ten thousand times."