 It was for many years the only Western-style building declared a national treasure, and is said to be the oldest church in Japan.In 1863, two French priests from the Société des Missions Étrangères, Fathers Louis Furet and Bernard Petitjean, landed in Nagasaki with the intention of building a church honoring the Twenty-Six Martyrs of Japan, nine European priests and seventeen Japanese Christians who were crucified in 1597 by order of Toyotomi Hideyoshi.The church was finished in 1864.