The Protestant Reformation of the sixteenth century marked a decisive recalibration in Christian theology and church life. What began as a series of theological disputes within the Western church soon produced lasting shifts in doctrine, worship, church government, and the locus of authority. The movement was not a single event but a constellation of reforming initiatives that returned the church to a renewed confidence in Scripture and in the gospel of God’s free grace. This article provides a compact account of those developments and draws lines of continuity to the concerns the Reformation Conference 2025 will treat: the authority of Scripture, justification, the marks of the true church, the means of grace, and the vocation of the church in society