Simplify the following text for a Grade 8 native English-speaking person.
Original: From Rome , Cimabue went to Assisi to paint several large frescoes at the newly-built Basilica of St Francis of Assisi , and it is possible , but not certain , that Giotto went with him .
Simplified: From Rome , Giotto 's teacher Cimabue went to Assisi to paint several large frescoes at the `` Upper Church '' of the newly-built Basilica of St. Francis of Assisi .