Simplify the following text for a Grade 12 native English-speaking person.
Original: Since the death of Queen Mary and the accession to the throne of her half-sister Elizabeth in 1558 , Catholic priests had been forced into hiding , but in remote areas like Lancashire they continued to celebrate mass in secret .
Simplified: Since the death of Queen Mary and the coming to the throne of her half-sister Elizabeth in 1558 , Catholic priests had been forced to hide , but in remote areas like Lancashire they were still able to celebrate mass in secret .