Amillennialism holds that Revelation 20’s ‘thousand years’ is not a literal future period but an allegory for the current church age — the reign of Christ is already happening spiritually in the church. Augustine of Hippo develops this interpretation in The City of God (~413–426 AD), partly in response to the failure of premillennial expectations and partly to address the Donatist crisis. Amillennialism becomes the dominant view in medieval Catholic theology and is retained by Luther, Calvin, and most of the Reformation’s magisterial (state church) streams. The ‘millennium’ is the age between Christ’s first and second comings — its ‘binding of Satan’ (Revelation 20:2) refers to the limitation of Satan’s power through the Gospel. Christ’s second coming will be followed immediately by the resurrection of the dead and final judgment, with no intervening earthly millennium.