Millerites were a religious group that emerged in the early 19th century, largely focused on the work of William Miller and his belief in the imminent Second Coming of Christ. While the term "Millerites" is the most commonly used to refer to this group, there are a number of synonyms that have been used over the years to describe them. Some of these include Adventists, Advent Believers, Second Adventists, and Millerite Adventists. Each of these terms emphasizes slightly different aspects of the group's beliefs and practices, but all are united in their focus on the apocalyptic teachings of William Miller and his followers.