Complex sentence: Despite this distinction, the use of gunpowder weapons "against" the castle resulted in it falling after only eight hours when it was besieged by Sir Thomas Wyatt in January 1554 during his unsuccessful rebellion against Queen Mary.
Split into simpler sentences: Despite this distinction, the use of gunpowder weapons "against" the castle proved devastating. It was captured after only eight hours when Sir Thomas Wyatt besieged it in January 1554 during his unsuccessful rebellion against Queen Mary.