Missionaries arrived not only from traditional churches, but also from some modern denominations, such as Jehovah's Witnesses. The Jehovah's Witnesses missionaries were so successful that they have become the second largest Christian denomination in Japan, with over 210,000 members (the largest is Catholicism with about 500,000 members). In Japan, Jehovah's Witnesses tend to be considered a Christianity-based Shinshūkyō, not only because they were founded in the 19th century (as were other major Shinshūkyō), but also because of their missionary practices, which involve door-to-door visiting and frequent meetings.