Complex sentence: In 1258 the monastery was heavily damaged by fire and later renewed until the period of the Hussite movement when it was attacked and plundered by the citizens of Prague in 1420.
Split into simpler sentences: In 1258 the monastery was heavily damaged by fire and later renewed. In this state the monastery remained until the period of the Hussite movement when it was attacked and plundered by the citizens of Prague in 1420.