Complex sentence: The new Edward IV visited the castle regularly and established a council there to govern his estates in Wales, but he probably conducted only modest work on the property, although he may could have been responsible for the remodelling of the Great Tower.
Split into simpler sentences: The new Edward IV visited the castle regularly and established a council there to govern his estates in Wales. He probably conducted only modest work on the property, although he may could have been responsible for the remodelling of the Great Tower.