Practically simultaneously with the construction of the Imperial Palace, the Collegiate Church of St. Simon and Judas was built at its foot, a building which would, over the next decades, be a model for numerous Romanesque churches both near and far. It was immensely influential in church politics: many canons attained the highest church offices, becoming bishops or advisors to the royal court.
In 1820 the desolate church was demolished; only the entry vestibule was left standing. Today outstanding examples of stone masonry and the decorative sandstone barriers of the Imperial Throne can be viewed.
