reformation

noun

• 1 [mass noun] the action or process of reforming an institution or practice:the reformation of the Senate

• 2 (the Reformation) a 16th-century movement for the reform of abuses in the Roman Church ending in the establishment of the Reformed and Protestant Churches.

The roots of the Reformation go back to the 14th-century attacks on the wealth and hierarchy of the Church made by groups such as the Lollards and the Hussites. But the Reformation is usually thought of as beginning in 1517 when Martin Luther issued ninety-five theses criticizing Church doctrine and practice. In Denmark, Norway, Sweden, Saxony, Hesse, and Brandenburg, supporters broke away and established Protestant Churches, while in Switzerland a separate movement was led by Zwingli and later Calvin