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On October 31, 2017 protestants will celebrate that historic day when Martin Luther nailed his 95 theses on the door of the castle church in Wittenberg, an act which shook the religious world of the time. 
The 500th Reformation anniversary also means a great deal to Heidelberg. The then capital of the Kurpfalz (the Electoral Palatinate) played an important role in the spreading of the new doctrine. On April 26, 1518, Martin Luther visited Heidelberg, residence of the Elector Princes. As in Wittenberg, he proclaimed his 95 theses and defended himself before the General Chapter of the Augustine monks at the famous Heidelberg Defense. The commemorative Luther plaque marks where the Augustine abbey once stood. In 1563 the famous Heidelberg Catechism was formulated, the most significant confessional document in the reformed Christian faith the world over.

Disponível em:<http://www.heidelberg-marketing.de/en/culture/500-years-reformation.html>Acessado em 13 de outubro de 2017 

In “The then capital of the Kurpfalz (the Electoral Palatinate) played an important role in the spreading of the new doctrine.”, the word spreading is a synonym of