Simplify the following text for a Grade 8 native English-speaking person.
Original: Cimabue may have been working in Rome in this period , and there was an active local school of fresco painters , of whom the most famous was Pietro Cavallini .
Simplified: Around 1280 , Giotto and Cimabue went to Rome , where there were several fresco painters . The most famous painter in Rome was Pietro Cavallini .