Beeldenstorm (ˈbeːldə(n)ˌstɔr(ə)m) in Dutch and Bildersturm ˈbɪldɐˌʃtʊʁm in German (roughly translatable from both languages as 'attack on the images or statues') are terms used for outbreaks of destruction of religious images that occurred in Europe in the 16th century, known in English as the Great Iconoclasm or Iconoclastic Fury. During these spates of iconoclasm, Catholic art and many forms of church fittings and decoration were destroyed in unofficial or mob actions by Calvinist Protestant crowds as part of the Protestant Reformation. Most of the destruction was of art in churches and public places.
The Dutch term usually specifically refers to the wave of disorderly attacks in the summer of 1566 that spread rapidly through the Low Countries from south to north. Similar outbreaks of iconoclasm took place in other parts of Europe, especially in Switzerland and the Holy Roman Empire in the period between 1522 and 1566, notably Zürich (in 1523), Copenhagen (1530), Münster (1534), Geneva (1535), and Augsburg (1537).
In England, there was both government-sponsored removal of images and also spontaneous attacks from 1535 onwards, and in Scotland from 1559. In France, there were several outbreaks as part of the Wars of Religion from 1560 onwards.
In France, unofficial episodes of large scale destruction of art in churches by Huguenot Calvinists had begun in 1560; unlike in the Low Countries, they were often physically resisted and repulsed by Catholic crowds, but were to continue throughout the French Wars of Religion. In Anglican England much destruction had already taken place in an organized fashion under orders from the government, while in Northern Europe, groups of Calvinists marched through churches and removed images, a move which "provoked reactive riots by Lutheran mobs" in Germany and "antagonized the neighbouring Eastern Orthodox" in the Baltic region.
In Germany, Switzerland and England, conversion to Protestantism had been enforced on the whole population at the level of a city, principality or kingdom, with varying degrees of discrimination, persecution or expulsion applied to those who insisted on remaining Catholic.