Yi Yong-hui Magdalene was born of a poor but noble family. Her mother, Ho Magdalene, her elder sister, Yi Barbara, and her aunt, Yi Theresa, were all fervent Catholics, but her father was a staunch pagan who hated the Catholics, so they had to practice their religion secretly. Her father tried to have Magdalene married to a pagan, but she wanted to live as a virgin and refused to abide by her father's wish. She decided to run away.
One day Magdalene told the young Catholic servant woman working at her home: "I hear that it is 12 kilometers from here to Seoul. My father is going to Seoul tomorrow. Please follow him, and I will follow you."
At night Magdalene put on old clothes and went out of her house carrying her usual clothes with her. The house was located in a forest. She went into the forest and cut herself enough to draw blood. She sprinkled her blood on the ground and on her clothes, which she ripped and scattered around the road. Early next morning her father left for Seoul, and the servant woman and Magdalene followed him. She went to her aunt, Yi Theresa. To her startled aunt, Magdalene told the whole story.
Meanwhile, in the country, her whole family tried to find Magdalene, who was missing. Her mother was very sad. One of Magdalene's uncles went into the forest and found traces of blood on the road and Magdalene's clothes stained with blood and all ripped. He rushed to Seoul and told Magdalene's father, who was with his sister, Yi Theresa, that Magdalene had been killed by a tiger. Magdalene's father fainted at the news. The only one who knew the whole story was Yi Theresa. Magdalene's father hired some hunters to catch the tiger in the forest. Three months elapsed. Magdalene's mother found out the whole story somehow and no longer showed her sadness. Magdalene's father asked her: "You are less sad now. Tell me the whole story. I promise not to oppose Magdalene's wish." Magdalene's mother told her husband the whole story. He rushed to Seoul and was very happy to find Magdalene safe at the home of Yi Theresa. He told her that he would not insist on her marriage, and allowed her to stay in Seoul.
Magdalene and three other pious women surrendered themselves to the police.
Magdalene was beheaded outside the Small West Gate on July 20, 1839, with seven other Catholics. She was 31 years old when her heavenly spouse crowned her with martyrdom.