Complex sentence: The new counts of Ravensberg and the owners of the Sparrenburg, the dukes of Cleves, ordered the expansion of the castle, dictating that it should be adjusted in order to withstand the more effective siege guns.
Split into simpler sentences: The new counts of Ravensberg and the owners of the Sparrenburg, the dukes of Cleves, ordered the expansion of the castle. It should be adjusted to the new military conditions, in order to withstand the more effective siege guns.