William Irvine (/ˈɜːrvɪn/; 1863–1947), sometimes Irvin or Irwin in contemporary documents, was an evangelist from the late nineteenth century, and continuing through the first half of the twentieth century. He is regarded as the founder and early propagator of the Two by Twos movement. Rapid growth was experienced in its initial decades, and Irvine eventually came into conflict with the regional overseers whom he had appointed to administer the now worldwide religion. Irvine was excommunicated by the overseers in 1914 and eventually moved to Jerusalem, supported by loyalists who followed him out of the movement. He spent his remaining years writing apocalyptic and prophetic letters to his remaining followers around the world from Jerusalem, where he died in March 1947.
