The Bible Student movement is a Millennialist Restorationist Christian movement. It emerged in the United States from the teachings and ministry of Charles Taze Russell (1852–1916), also known as Pastor Russell, and his founding of the Zion's Watch Tower Tract Society in 1881. Members of the movement have variously referred to themselves as Bible Students, International Bible Students, Associated Bible Students, or Independent Bible Students.
A number of schisms developed within the congregations of Bible Students associated with the Watch Tower Society between 1909 and 1932. The most significant split began in 1917 following the election of Joseph Franklin Rutherford as president of the Watch Tower Society two months after Russell's death. The schism began with Rutherford's controversial replacement of four of the Society's board of directors and publication of The Finished Mystery in July 1917.