The Moravian Church's founding predates the Protestant Reformation commonly dated to Martin Luther's 1517 theses by sixty years, a fact its members have long taken as a point of quiet pride. Its roots lie in the reform movement begun a century earlier by the Bohemian priest Jan Hus, burned as a heretic in 1415, whose followers, the Hussites, won a measure of toleration in Bohemia but soon split between a moderate wing that stayed close to Rome and radicals who wanted a more thorough reformation. Among the latter, a group gathered around the lay theologian Petr Chelcicky, who taught a strict, nonviolent, Scripture-centered discipleship, and in 1457 followers of this teaching organized a distinct fellowship at Kunvald, in eastern Bohemia, under the leadership of a figure remembered as Gregory the Patriarch.
The new body, calling itself the Unitas Fratrum, the Unity of the Brethren, established its own three-fold ordained ministry of deacons, presbyters, and bishops within a decade, and by the early sixteenth century it counted several hundred parishes and perhaps two hundred thousand members across Bohemia and Moravia. The Catholic Counter-Reformation and the devastation of the Thirty Years' War in the following century very nearly extinguished the church; most of its congregations were destroyed or forced underground, and its surviving members, scattered across Central Europe in secret, became known to later Moravian history as the Hidden Seed.