Complex sentence: The castle is first mentioned in history books in 1220, but historians figure it from the 10/11 Century AD, an earthquake in 1511 led to its reconstruction as the building it became during the battle.
Split into simpler sentences: The castle is first mentioned in history books in 1220, but historians estimate that it was built in the 10th or 11th century. An earthquake in 1511 led to its reconstruction into the form it took during the battle.