Owing to both their Danish past and American present, Protestantism on the islands has long been widespread. It was first introduced when Lutheranism was brought to the islands in the Danish colonization. The Danish crown also allowed other religious traditions on the islands including Anglicanism, Roman Catholicism, the Moravian Church and other Protestant groups. Historically, St. Thomas and St. Croix are known for missionary efforts undertaken by the Moravian missionaries. They were allowed on the islands by the Danish royal court, but came under scrutiny when they denounced slavery. A number of neo-Protestant traditions including Pentecostalism, various evangelical Protestants and the Seventh-day Adventists arrived later with the switch of allegiance from Denmark to the United States.