Christianity arrived in Korea during the Japanese invasion of 1592 when some Koreans were baptized, probably by Christian Japanese soldiers. Evangelization was difficult because Korea refused all contact with the outside world. The first native Korean priest, Andrew Kim Taegon, was the son of Christian converts. Following his baptism at 15, Andrew traveled to the seminary in Macao, China. After six years, he returned to his country through Manchuria, and then he crossed the Yellow Sea to Shanghai for his priestly ordination. Once he returned home, he was assigned to arrange for more missionaries to enter by a water route that would elude the border patrol. He was arrested, tortured, and eventually beheaded at the Han River near Seoul. Andrew's father, Ignatius Kim, and Paul Chong Hasang, a lay apostle, were martyred during the persecution of 1839. Ignatius Kim was beatified in 1925. When he visited Korea in 1984, Pope John Paul II canonized Andrew and Paul, as well as 98 Koreans and three French missionaries who had been martyred between 1839 and 1867. Among them were bishops and priests, but for the most part they were lay persons.