Speyer was one of the great cities of the Holy Roman Empire, founded in pre-Celtic times, taken over by the Romans, and expanded in the 11th century by the Salian emperors. Between 1294, when it was declared a Free Imperial City, and 1570, no fewer than 50 imperial diets were convened here. The term "Protestant" derives from the Diet of 1529, referring to those who protested when the religious freedom granted to evangelicals
at the Diet of 1526 was revoked and a return to Catholicism was decreed. The neo-Gothic Gedächtniskirche on Bartolomäus-Weltz-Platz commemorates those 16th-century Protestants.