Kim Sŏng-u Anthony was born in 1794 and lived in Kusan in Kyŏnggi Province. He was honest and generous and known to be rich. According to a witness, Anthony was a man of warm personality and generosity and he was respected even by non-Catholics. His great grandchildren, like their grandfather, were later widely respected in their home village.
Anthony and his relatives heard about the Catholic religion, and they all became believers. Finally his whole village became Catholic.
After his mother died, he moved to Seoul and lived outside the East Gate. His two younger brothers remained in Kusan and both of them were arrested. The older one, Augustine. died in prison in May of 1841 at the age of 43 and the second one suffered in prison for a long time. After his wife died, he remarried another very devout Catholic woman.
After the missionaries came to Korea, Anthony provided a small chapel in his house, where Father Maubant offered Mass quite frequently.
At the end of 1839 a traitor accused Anthony to the government and the whole family was arrested and sent to prison in January of 1840. He was severely tortured. To the police chief, who demanded that he deny his faith, he said that he would die as a Catholic. Even in prison he acted normally, as if he were at home. He didn't express any desire to be released. Even non-Catholic inmates liked him and two pagan inmates were instructed and baptized by him.
By the end of April of 1841 he was interrogated and tortured again. On April 29, 1841, he was strangled to death at the age of 47. He had been in prison for 15 months. His body was brought home and solemnly buried in Kusan, and transferred to the Major Seminary in Yongsan (in Seoul) in 1927. His remains are now preserved in Kusan Martyrs' Shrine.