The evangelization of Korea began during the 17th century through a group of lay persons. A strong vital Christian community flourished there under lay leadership until missionaries arrived from the Paris Foreign Mission Society.

During the terrible persecutions that occurred in the 19th century (in 1839, 1866, and 1867), one hundred and three members of the Christian community gave their lives as martyrs. Outstanding among these witnesses to the faith were the first Korean priest and pastor, Andrew Kim Taegon, and the lay apostle, Paul Chong Hasang.

Among the other martyrs were a few bishops and priests, but for the most part lay people, men and women, married and unmarried, children, young people, and the elderly. All suffered greatly for the Faith and consecrated the rich beginnings of the Church of Korea with their blood as martyrs.

Pope John Paul II, during his trip to Korea, canonized these martyrs on May 6, 1984, and inserted their feast into the Calendar of the Universal Church.