Pope Francis on the popemobile, is greeted by the faithful upon arrival for the beatification mass of Paul Yun Ji-Chung and his 123 martyr companions, in Seoul, South Korea, Saturday. Pic: AP.

SEOUL, South Korea (AP) — Hundreds of thousands of people have turned out for one of the highlights of Pope Francis’ trip to South Korea: a beatification Mass for 124 Koreans killed for their faith over two centuries ago.

The streets leading up to Seoul’s iconic Gwanghwamun Gate were packed Saturday with Koreans honoring the ordinary lay Catholics who founded the church in the 18th century.

(MORE: Sewol tragedy families seek Pope’s support in search for justice)

Korea’s church is unique in that it was founded not by missionaries or priests who brought the faith to the peninsula and converted people — as occurred in most of the world — but by members of Korea’s own noble classes who learned of Catholicism by reading books about it.

Francis was beatifying 124 of these early Catholics who were killed by the Joseon Dynasty, which opposed Western influences.