Simplify the following text for a Grade 6 native English-speaking person.
Original: While in Bologna he became a deacon , and by 1428 he was a priest . Cardinal Aleman was driven from Bologna by the rival Canedoli family in 1428 , and Dufay also left at this time , going to Rome .
Simplified: When the Cardinal was made to leave Bologna in 1428 Dufay went to Rome to work for the pope .