Ellen Gould White (née Harmon; November 26, 1827 -- July 16, 1915) was a prolific author and an American Christian pioneer. She, along with other Sabbatarian Adventist leaders, such as Joseph Bates and her husband James White, formed what is now known as the Seventh-day Adventist Church.
Ellen White reported to her fellow believers her visionary experiences. James White, and others of the Adventist pioneers, viewed these experiences as the Biblical gift of prophecy as outlined in Revelation 12:17 and Revelation 19:10 which describe the testimony of Jesus as the "spirit of prophecy." Her Conflict of the Ages series of writings endeavor to showcase the hand of God in Biblical and Christian church history. This cosmic conflict, referred to as the "Great Controversy theme", is foundational to the development of Seventh-day Adventist theology.